Systems and methods for separating multi-phase compositions

ABSTRACT

Separators for separating a multi-phase composition include a separator casing defining a chamber and a permeate outlet, at least one hydrocyclone within the separator casing, and at least one ceramic membrane. Each hydrocyclone includes a hydrocyclone inlet, a tapered section downstream of the hydrocyclone inlet, an accepted outlet, and a reject outlet. The ceramic membrane may be disposed within the separator casing and downstream of the accepted outlet of the hydrocyclone or may be disposed within at least a portion of the tapered section of the hydrocyclone. The ceramic membrane includes a retentate side and a permeate side, where the permeate side is in fluid communication with the chamber. Systems and methods for separating a multi-phase composition into a lesser-density fluid, a greater-density fluid, and a medium-density fluid using the separators are also disclosed.

TECHNICAL FIELD

The present disclosure generally relates to apparatus, systems, andmethods for separating compositions comprising multiple phases, inparticular, systems and methods of separating compositions that includean aqueous phase, an oleaginous phase, and a solid phase into aplurality of different streams having different densities.

BACKGROUND

Petroleum drilling, production, and/or refining can produce variousmixed phase streams, such as produced water, that contain an aqueousphase, an oleaginous phase, and a solid phase in the form of solidparticulates. Produced water is the largest mixed phase stream producedin the oil and gas industry and is produced in estimated amounts of 3:1produced water to crude oil on a volume basis. The oleaginous phase ofproduced water and other mixed phase streams may include organiccompounds, such as oils, phenolic compounds and other organic andinorganic contaminants. Many of these organic and inorganic contaminantsmust be removed from the aqueous streams before the water from theseaqueous streams can be reused in drilling operations and refiningprocesses or directed to downstream treatment processes. Additionally,solid components of the produced water or other mixed phase stream arealso generally removed prior to reuse in drilling and refiningoperations or treatment in a downstream treatment process.

SUMMARY

Multi-phase compositions, such as produced water, may be separated intoone or more streams by various techniques, which may include gravity oilseparation (settling), membrane separation, filtering, gas flotation,centrifugal separation, hydrocyclonic separation, distillation, or otherseparation processes. Membrane separation or filtration processes mayprovide for efficient separation of solid particles from multi-phasecompositions. However, membranes and filters can be susceptible tobio-fouling from the oleaginous constituents and organic compounds.Bio-fouling of membranes and filters can result in constant replacementof membranes and filters. Hydrocyclones can be used to remove oildroplets and other organic compounds from multi-phase compositions, butare ineffective at efficiently removing solid particles. Other separatorsystems, such as gravity oil separators, gas flotation systems, anddistillation systems can have substantial space requirements.Additionally, systems combining multiple separation units in series orparallel may also have large space requirements. The space requirementsof certain separation unit operations and combinations of separationequipment may be impractical for applications with limited physicalspace, such as well-drilling operations, in particular well-drillingplatforms for underwater drilling. Many physical separation devices mayalso be limited in the size range of oil droplets that are able to beremoved from multi-phase compositions.

Accordingly, ongoing needs exist for improved apparatus, systems, andmethods for separating multi-phase compositions. In particular, ongoingneeds exist for apparatus and systems that have a reduced size footprintcompared to existing separation processes and are capable of separatinga multi-phase composition into a plurality of streams with reducedbio-fouling that can disrupt operation of the separation equipment. Theseparators and separator systems of the present disclosure include aseparator casing, one or a plurality of hydrocyclones, and one or aplurality of ceramic membranes, where the hydrocyclones and the ceramicmembranes are disposed within the separator casing. The ceramicmembranes may be disposed downstream of an accepted outlet of thehydrocyclone or may be integrated into a tapered section of thehydrocyclone. The separator having one or more ceramic membranesintegrated with a hydrocyclone may be operable to separate a multi-phasecomposition into at least a lesser-density fluid, a medium-densityfluid, and a greater-density fluid. The separators of the presentdisclosure may have a reduced size footprint and reduced bio-foulingcompared to existing separation equipment and processes. The separatorsand separator systems of the present disclosure may also be capable toproducing a medium-density fluid comprising water that may meet orexceed water quality specifications for re-use of the water inhydrocarbon drilling, production, and refining operations, among othercapabilities that are or may become apparent from the presentdisclosure.

According to one or more aspects of the present disclosure, a separatormay include a separator casing defining a chamber and having a permeateoutlet, at least one hydrocyclone disposed within the separator casing,and at least one ceramic membrane disposed within the separator casingand downstream of an accepted outlet of the hydrocyclone. The at leastone hydrocyclone may include a hydrocyclone inlet, a tapered sectiondownstream of the hydrocyclone inlet, a reject outlet proximate a wideend of the tapered section, and an accepted outlet proximate a narrowend of the tapered section. The ceramic membrane may include at leastone cylindrical tube, a membrane inlet, a retentate outlet, a retentateside defining the at least one cylindrical tube, and a permeate side,where the permeate side is in fluid communication with the chamber.

According to one or more other aspects of the present disclosure, aseparator system may include a separator. The separator may include aseparator casing defining a chamber and having a permeate outlet, atleast one hydrocyclone disposed within the separator casing and havingan accepted outlet and a reject outlet, and at least one ceramicmembrane disposed within the separator casing and downstream of theaccepted outlet of the hydrocyclone, the ceramic membrane comprising atleast one cylindrical tube, a membrane inlet, a retentate outlet, aretentate side defining the at least one cylindrical tube, and apermeate side, where the permeate side is in fluid communication withthe chamber. The separator system may further include at least onepressure sensor operatively coupled to the hydrocyclone inlet, thereject outlet, the membrane inlet, the retentate outlet of the ceramicmembrane, or the separator casing. The separator system may furtherinclude at least one control valve operatively coupled to a permeateoutlet or a greater-density fluid outlet of the separator casing, atleast one processor communicatively coupled to the at least one pressuresensor and the at least one control valve, and at least one memorymodule communicatively coupled to the processor.

According to one or more other aspects of the present disclosure, amethod of separating a multi-phase composition having an aqueous phase,an oleaginous phase, and a solid phase, may include passing themulti-phase composition to a separator operable to separate themulti-phase composition into a lesser-density fluid, a medium-densityfluid, and a greater-density fluid. The separator may include aseparator casing defining a chamber and having a permeate outlet, atleast one hydrocyclone disposed within the separator casing and havingan accepted outlet and a reject outlet, and at least one ceramicmembrane disposed within the separator casing and downstream of theaccepted outlet of the hydrocyclone, the ceramic membrane comprising atleast one cylindrical tube, a membrane inlet, a retentate outlet, aretentate side defining the at least one cylindrical tube, and apermeate side, where the permeate side is in fluid communication withthe chamber.

Additional features and advantages of the present disclosure will be setforth in the detailed description that follows, and in part will bereadily apparent to those skilled in the art from that description orrecognized by practicing the described subject matter, including thedetailed description that follows, the claims, as well as the appendeddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of specific aspects of the presentdisclosure can be best understood when read in conjunction with thefollowing drawings, in which like structure is indicated with likereference numerals and in which:

FIG. 1 schematically depicts a separator for separating a multi-phasecomposition, according to one or more embodiments shown and described inthe present disclosure;

FIG. 2 schematically depicts operation of a hydrocyclone, in partialsectional view, of the separator of FIG. 1, according to one or moreembodiments shown and described in the present disclosure;

FIG. 3 schematically depicts a separator system comprising the separatorof FIG. 1, according to one or more embodiments shown and described inthe present disclosure;

FIG. 4 schematically depicts another embodiment of a separator systemcomprising the separator of FIG. 1, according to one or more embodimentsshown and described in the present disclosure;

FIG. 5 schematically depicts another embodiment of a separator,according to one or more embodiments shown and described in the presentdisclosure;

FIG. 6 schematically depicts a ceramic membrane assembly forincorporating a ceramic membrane into a tapered section of ahydrocyclone of the separator of FIG. 5, according to one or moreembodiments shown and described in the present disclosure;

FIG. 7 schematically depicts still another embodiment of a separator,according to one or more embodiments shown and described in the presentdisclosure;

FIG. 8A schematically depicts a separator system comprising theseparator of FIG. 5, according to one or more embodiments shown anddescribed in the present disclosure;

FIG. 8B schematically depicts another separator system comprising theseparator of FIG. 5, according to one or more embodiments shown anddescribed in the present disclosure;

FIG. 9 schematically depicts another embodiment of a separator systemcomprising the separator of FIG. 5, according to one or more embodimentsshown and described in the present disclosure;

FIG. 10 schematically depicts a separator system comprising theseparator of FIG. 7, according to one or more embodiments shown anddescribed in the present disclosure;

FIG. 11 graphically depicts a pressure drop between a hydrocyclone inletand an accepted outlet (y-axis) as a function of inlet flowrate (x-axis)for a hydrocyclone of the separator of FIG. 1, according to one or moreembodiments shown and described in the present disclosure;

FIG. 12 graphically depicts a specific permeate flux (y-axis) as afunction of a transmembrane pressure (x-axis) for a ceramic membrane ofthe separator of FIG. 1, according to one or more embodiments shown anddescribed in the present disclosure;

FIG. 13 schematically depicts a separator having a plurality ofhydrocyclones and a plurality of ceramic membranes, according to one ormore embodiments shown and described in the present disclosure; and

FIG. 14 schematically depicts another separator having a plurality ofhydrocylones and a plurality of ceramic membranes, according to one ormore embodiments shown and described in the present disclosure.

For purposes of describing the simplified schematic illustrations anddescriptions in FIGS. 1-10, the numerous valves, temperature sensors,flow meters, pressure regulators, electronic controllers, pumps, and thelike that may be employed and well known to those of ordinary skill inthe art of certain chemical and oilfield processing operations may notbe depicted. Further, accompanying components that are often included intypical chemical and oilfield processing operations, such as valves,pipes, pumps, agitators, heat exchangers, instrumentation, internalvessel structures, or other subsystems may not be depicted. Though notdepicted, it should be understood that these components are within thespirit and scope of the present embodiments disclosed. However,operational components, such as those described in the presentdisclosure, may be added to the embodiments described in thisdisclosure.

Arrows in the drawings refer to process streams. However, the arrows mayequivalently refer to transfer lines, such as pipes or conduits, whichmay serve to transfer process streams between two or more systemcomponents. Additionally, arrows that connect to system components maydefine inlets or outlets in each given system component. The arrowdirection corresponds generally with the major direction of movement ofthe materials of the stream contained within the physical transfer linesignified by the arrow. Furthermore, arrows which do not connect two ormore system components may signify a product stream which exits thedepicted system component or a system inlet stream which enters thedepicted system or system component.

Additionally, arrows in the drawings may schematically depict processsteps of transporting a stream or composition from one system componentto another system component. For example, an arrow from one systemcomponent pointing to another system component may represent “passing” astream or composition to another system component, which may include thecontents of a process stream “exiting” or being “removed” from onesystem component and “introducing” the contents of that product streamto another system component.

Reference will now be made in greater detail to various aspects of thepresent disclosure, some aspects of which are illustrated in theaccompanying drawings.

DETAILED DESCRIPTION

The present disclosure is directed to separators, separator systems, andmethods for separating multi-phase compositions, such as produced water,into a plurality of fluids of different densities. Referring to FIG. 1,an embodiment of a separator 100 of the present disclosure isschematically depicted. The separators 100 of the present disclosure mayinclude a separator casing 110 defining a chamber 112 and having apermeate outlet 114. The separators 100 may also include one or aplurality of hydrocyclones 130 disposed within the separator casing 110.Each of the hydrocyclones 130 may include a hydrocyclone inlet 132, atapered section 138 downstream of the hydrocyclone inlet 132, a rejectoutlet 134 proximate a wide end of the tapered section 138, and anaccepted outlet 136 proximate the narrow end of the tapered section 138.The separator 100 may also include one or a plurality of ceramicmembranes 150 disposed within the separator casing 110. The ceramicmembrane(s) 150 may include one or a plurality of cylindrical tubes 151,a membrane inlet 152, a retentate outlet 154, a retentate side 156defining the cylindrical tubes 151, and a permeate side 158. Thepermeate side 158 may be in fluid communication with the chamber 112.The ceramic membranes 150 may be disposed downstream of the acceptedoutlet 136 of the hydrocyclone 130. Referring to FIG. 5, anotherembodiment of a separator 200 of the present disclosure is depicted inwhich a ceramic membrane 250 can be integrated into a tapered section238 of a hydrocyclone 230 such that the ceramic membrane 250 forms thewalls 242 of the hydrocyclone 230 in at least a portion of the taperedsection 238. The present disclosure also includes separator systems thatinclude pressure differential control, flowrate control, or both, of theseparators 100, 200.

The separators 100, 200 and separator systems of the present disclosuremay be operable to separate a multi-phase composition 102, such asproduced water, having an aqueous phase, an oleaginous phase, andsolids, into at least a lesser-density fluid 104, a greater-densityfluid 106, and a medium-density fluid 108. The cyclonic flow produced inthe hydrocyclone 130, 230 may be operable to separate an oleaginousphase from the multi-phase composition 102, which may be passed out ofthe hydrocyclone 130, 230 from the reject outlet 134, 234. Cyclonic flowin the hydrocyclone 130, 230 and removal of the oleaginous components ofthe multi-phase composition 102 may reduce bio-fouling of the ceramicmembranes 150, 250, whether downstream of the hydrocyclone 130 orintegrated into the tapered section 238 of hydrocyclone 230. Theseparators 100, 200 and separator systems of the present disclosure maybe operable to separate a greater range of oil droplet sizes from themulti-phase composition 102 compared to existing commercially-availableseparation processes. The separators 100, 200 of the present disclosureintegrating the hydrocyclone 130, 230 and ceramic membrane 150, 250 intoa single separator casing 110, 210 may have a compact footprint toenable use of the separators 100, 200 in locations with limited spacerequirements, such as drilling platforms or other operations.

The term “or”, as used in the present disclosure, is inclusive; morespecifically, the phrase “A or B” means “A, B, or both A and B.”Exclusive “or” is designated in the present disclosure by terms such as“either A or B” and “one of A or B,” for example.

The indefinite articles “a” and “an” are employed to describe elementsand components of the present disclosure. The use of these articlesmeans that one or at least one of these elements or components ispresent. Although these articles are conventionally employed to signifythat the modified noun is a singular noun, as used herein the articles“a” and “an” also include the plural, unless otherwise stated inspecific instances. Similarly, the definite article “the”, as used inthe present disclosure, also signifies that the modified noun may besingular or plural, again unless otherwise stated in specific instances.

As used in the present disclosure, the terms “upstream” and “downstream”refer to the positioning of components of the separator 100, 200relative to the direction of flow of materials through the separator100, 200. For example, a first component may be considered “upstream” ofa second component if materials flowing through the separator 100, 200encounter the first component before encountering the second component.Likewise, the second component is considered “downstream” of the firstcomponent if the materials flowing through the separator 100, 200encounter the first component before encountering the second component.

As used in the present disclosure, the term “fluid” may be used to referto a flowable composition that includes gases, one or a plurality ofliquids, or mixtures of liquids with gases, solids, or both. Fluids caninclude, but are not limited to, liquids and liquid mixtures, gas-liquidemulsions, liquid-liquid emulsions, dispersions, solutions, andsuspensions.

As used in the present disclosure, the term “multi-phase composition”may refer to a composition that includes two or more phases, which mayinclude, but are not limited to, solids, gases, and one or more liquidphases. The liquid phases may include one or more immiscible liquidphases, such as an aqueous phase and an oleaginous phase.

As used in the present disclosure, the term “permeate” may refer to thematerials that pass through a ceramic membrane from the retentate sideto the permeate side. The term “permeate” is not intended to imply anyparticular mass transport phenomenon or mechanism, such as but notlimited to diffusion, osmosis, filtration, or other such mechanism.

As used in the present disclosure, the term “reject outlet” may refer tothe outlet of a hydrocyclone from which the lesser-density constituentsof the multi-phase composition exit the hydrocyclone. The term “acceptedoutlet” may refer to the outlet of the hydrocyclone from which theconstituents other than the lesser-density constituents of themulti-phase composition exit the hydrocyclone.

Referring again to FIG. 1, the separators 100 of the present disclosuremay include the separator casing 110, at least one hydrocyclone 130disposed within the separator casing 110, and at least one ceramicmembrane 150 disposed within the separator casing 110 and downstream ofthe hydrocyclone 130. The separator casing 110 may define a chamber 112and may include a permeate outlet 114. The hydrocyclones 130 and theceramic membranes 150 may be disposed within the chamber 112 defined bythe separator casing 114.

The hydrocyclone 130 may be a mechanical device operable to separatelesser-density constituents of the multi-phase composition 102, such asbut not limited to oil droplets, from the greater-density constituentsof the multi-phase composition 102, such as solid particles, water,salts, or other aqueous constituents. The multi-phase composition 102may include a plurality of phases, such as 2, 3, 4, or more than 4phases. The multi-phase composition 102 may include a gaseous phase, oneor more liquid phases, a solid phase, or combinations of these. In oneor more embodiments, the multi-phase composition 102 may include anaqueous phase comprising primarily water and water-soluble constituents,an oleaginous phase comprising primarily oil droplets and other organiccompounds, and a solid phase comprising solid particles, such assuspended solids. In one or more embodiments, the multi-phasecomposition 102 may be produced water that includes an aqueous phase, anoleaginous phase comprising at least oil droplets, and a solid phasecomprising at least suspended solids. Embodiments of the separators 130of the present disclosure are described in the context of treatingproduced water from hydrocarbon drilling, production, and refining.However, it is understood that the separators 130 of the presentdisclosure may be applied to various other multi-phase compositions.

The hydrocyclone 130 may operate by generating a cyclonic or vortex flowthat creates centrifugal forces within the multi-phase composition 102.The centrifugal forces may cause the greater-density constituents of themulti-phase composition 102 to travel or migrate radially outward from acenter axis A of the hydrocyclone 130 towards the walls 142 of thehydrocyclone 130. The hydrocyclone 130 may include a cylindrical inletchamber 144 and the tapered section 138 downstream of the cylindricalinlet chamber 144. The tapered section 138 may be frusto-conical inshape having a wide end and a narrow end, where the wide end has agreater diameter than the narrow end. The wide end may be disposed at anupstream end of the tapered section 138, and the narrow end may bedisposed downstream of the wide end of the tapered section 138. The wideend of the tapered section 138 may be coupled to the cylindrical inletchamber 144. The tapered section 138 may be defined by a cone angle αand a length LT of the tapered section 238. The cone angle α, length LTof the tapered section 238, and overall length L of the hydrocyclone 130may be selected based on the characteristics and composition of themulti-phase composition 102.

The hydrocyclone 130 may include a hydrocyclone inlet 132. Thehydrocyclone inlet 132 may be coupled to the cylindrical inlet chamber144 and may be configured to introduce the multi-phase composition 102to the hydrocyclone 130 in a manner that creates the cyclonic flow inthe hydrocyclone 130. The hydrocyclone inlet 132 may be tangent to theinner cylindrical surface of the cylindrical inlet chamber 144. In oneor more embodiments, the hydrocyclone inlet 132 may be coupled to thecylindrical inlet chamber 144 so that the hydrocyclone inlet 132 isgenerally parallel with a plane that is tangent to the cylindrical inletchamber 144.

The reject outlet 134 of the hydrocyclone 130 may be in fluidcommunication with the cylindrical inlet chamber 144 of the hydrocyclone130 and may be aligned with and centered on the center axis A of thehydrocyclone 130. The reject outlet 134 may be coupled to thecylindrical inlet chamber 144 at an end opposite the tapered section138. The reject outlet 134 may include an open-ended conduit or tubethat extends at least partially into the cylindrical inlet chamber 144.The open-ended conduit may reduce or prevent the multi-phase composition102 introduced to the hydrocyclone 130 from flowing directly into thereject outlet 134 without being subjected to the cyclonic flow withinthe hydrocyclone 130. The accepted outlet 136 of the hydrocyclone 130may be positioned at the narrow end of tapered section 138, the narrowend being at a distal end of the tapered section 138 relative to thecylindrical inlet chamber 144. In other words, accepted outlet 136 ofthe hydrocyclone 130 may be positioned at a downstream end of thetapered section 138 relative to the upstream end, which is coupled tothe cylindrical inlet chamber 144. The accepted outlet 136 may bealigned with and centered on the center axis A of the hydrocyclone 130.

The hydrocyclone 130 may be operable to separate the multi-phasecomposition 102, which may include a solid phase, an aqueous phase, andan oleaginous phase, into a lesser-density fluid 104 and an intermediatefluid stream 140. Referring now to FIG. 2, operation of the hydrocyclone130 is schematically depicted. The multi-phase composition 102 may beintroduced tangentially to the cylindrical inlet chamber 144 of thehydrocyclone 130 through the hydrocyclone inlet 132. The tangentialorientation of the hydrocyclone inlet 132 relative to the cylindricalinlet chamber 144 may cause the multi-phase composition 102 to flowalong the walls of the cylindrical inlet chamber 144 to create cyclonicflow. At the tapered section 138, the cross-sectional area of thehydrocyclone 130 decreases, which accelerates the multi-phasecomposition 102 in the cyclonic flow and generates greater centrifugalforces within the multi-phase composition 102. The increased centrifugalforces caused by the acceleration of the fluid in the tapered section138 may cause the greater-density constituents of the multi-phasecomposition 102 to travel radially outward towards the walls 142 of thehydrocyclone 130 and may cause the lesser-density constituents of themulti-phase composition 102 to travel radially inward towards the centeraxis A of the hydrocyclone 130. The greater-density constituents mayinclude, but are not limited to, solids and aqueous phase constituentshaving a greater density than the lesser-density constituents. Thelesser-density constituents may include oil droplets and other organicshaving a lesser density than the greater-density constituents.

The greater-density constituents may travel in a primary vortex flowalong the walls 142 of the tapered section 138 downstream towards theaccepted outlet 136 (in the −X direction of the coordinate axis of FIG.2). The primary vortex flow of the greater-density constituents withinthe hydrocyclone 130 is indicated in FIG. 2 with reference number 107.The lesser-density constituents may form a secondary vortex 105 at thecenter of the hydrocyclone 130. The secondary vortex 105 may create flowof the lesser-density constituents in a direction opposite the primaryvortex flow 107. The secondary vortex 105 may create flow of thelesser-density constituents towards the reject outlet 134 of thehydrocyclone 130 (+X direction of the coordinate axis of FIG. 2).

Referring to FIGS. 1 and 2, the lesser-density constituents may pass outof the hydrocyclone 130 from the reject outlet 134 as the lesser-densityfluid 104. The lesser-density fluid 104 may have a greater concentrationof oil droplets, organic compounds, or both, compared to the multi-phasecomposition 102. The lesser-density fluid 104 may have a lesserconcentration of suspended solids, water, and aqueous constituentsrelative to the multi-phase composition 102. The greater-densityconstituents may pass out of the hydrocyclone 130 from the acceptedoutlet 136 as an intermediate fluid stream 140. The intermediate fluidstream 140 may include an increased concentration of solids, water, andaqueous constituents compared to the multi-phase composition 102 and thelesser-density fluid 104. The intermediate fluid 140 may be a mixture ofthe greater-density fluid 106 and the medium-density fluid 108, whichmay be subsequently separated by the downstream ceramic membranes 150.The intermediate fluid 140 may have a concentration of oil droplets andother organic constituents that is less than the concentration of oildroplets and organic constituents in the multi-phase composition 102,the lesser-density fluid 104, or both. The reduced concentration of theoleaginous components in the intermediate fluid 140 may reducebio-fouling of the ceramic membranes 150 downstream of the hydrocyclone130.

For ease of illustration and description, the separator 100 of thepresent disclosure is described in the context of a having a singlehydrocyclone 130. However, it is understood that any of the separators100 of the present disclosure may include a plurality of hydrocyclones130 disposed within the separator casing 110. Referring now to FIG. 13,the separator 100 may have a plurality of hydrocyclones 130, such as 2,3, 4, 5, 6, or more than 6 hydrocyclones 130 disposed within theseparator casing 110. Such a layout may enable a number of hydrocyclones130 to operate in parallel under the same process conditions, thus,increasing the flow capacity of the separator 100 while reducing thespatial footprint and the costs associated with manufacturing and siteinstallation. In one or more embodiments, the separator 100 may includeup to several dozen hydrocyclones 130 disposed within the separatorcasing 110.

Referring again to FIG. 1, the separator 100 may include at least oneceramic membrane 150 disposed within the separator casing 110. Theseparator 100 may include one or more than one ceramic membrane 150,such as 1, 2, 3, 4, 5, 6, or more than 6 ceramic membranes 150.Increasing the number of ceramic membranes 150 may be operable toincrease the flowrate of the intermediate fluid stream 140 through theseparator 100 by increasing the total surface area of the ceramicmembranes 150. The ceramic membranes 100 may be disposed downstream ofthe accepted outlet 136 of the hydrocyclone 130. Each of the ceramicmembranes 150 may include one or a plurality of cylindrical tubes 151passing through the ceramic membrane 150 from a membrane inlet 152 to aretentate outlet 154. Each ceramic membrane 150 may include 1, 2, 3, 4,5, or more than 5 cylindrical tubes 151. The cylindrical tubes 151 ofthe ceramic membrane 150 may be defined by the retentate side 156 of theceramic membrane 150. The retentate side 156 may be the surfaces of theceramic membrane 150 oriented toward the center of each of thecylindrical tubes 151 of the ceramic membrane 150 in a directionradially inward from the permeate side 158. The ceramic membrane 150 mayhave a permeate side 158, which may be an outer surface of the ceramicmembrane 150. The permeate side 158 may be in fluid communication withthe chamber 112. The combination of the number of ceramic membranes 150,the number of cylindrical tubes 151 per ceramic membrane 150, and theinner diameter of the cylindrical tubes 151 may be selected based on theinlet flowrate of the multi-phase composition so that the linear speedof the intermediate fluid 140 through the cylindrical tubes 151 definedby the ceramic membranes 130 may be in a range of from 3 meters persecond (m/s) to 5 m/s.

The membrane inlets 152 of the at least one ceramic membrane 150 may bein fluid communication with the accepted outlet 136 of the hydrocyclone150. In one or more embodiments, the separator 100 may include aplurality of ceramic membranes 150 disposed within the separator casing110 and the membrane inlet 152 of each of the plurality of ceramicmembranes 150 may be in fluid communication with the accepted outlet 136of the hydrocyclone 130 or plurality of hydrocyclones 130. As used inthe present disclosure, the term “in fluid communication” may refer to arelationship between two components of the separator 100 in which afluid can be passed from one component directly to the second componentwithout passing the fluid first through a third component that changesthe composition or characteristics of the fluid. The permeate side 158of each of the plurality of ceramic membranes 150 may be in fluidcommunication with the chamber 112 defined by the separator casing 110.The ceramic membranes 150 may be oriented within the separator casing110 so that the flow of the intermediate stream 140 through thecylindrical tubes 151 of the ceramic membranes 150 is in a directionparallel to but opposite from the direction of flow through thehydrocyclone 130 (in the +X direction of the coordinate axis in FIG. 1).Alternatively, the ceramic membranes 150 may also be oriented so thatthe direction of flow through the ceramic membranes 150 is in the samedirection as the flow through the hydrocyclone 130 (−X direction of thecoordinate axis of FIG. 1) or non-parallel relative to the direction offlow through the hydrocyclone 130.

The retentate outlets 154 of each of the ceramic membranes 150 may be influid communication with a greater-density fluid outlet 124 of theseparator casing 110. In one or more embodiments, the separator 100 mayinclude a single greater-density fluid outlet 124 and each retentateoutlet 154 of the plurality of ceramic membranes 150 may be in fluidcommunication with the greater-density fluid outlet 124. In otherembodiments, the separator 100 may include a plurality ofgreater-density fluid outlets 124 and the retentate outlet 154 of eachof the ceramic membranes 150 may be in fluid communication with one ofthe plurality of greater-density fluid outlets 124. The retentate outlet154 of each of the ceramic membranes 150 may be fluidly coupled to oneof the greater-density fluid outlets 124 by a conduit (not shown). Inone or more embodiments, the retentate outlet 154 of each of the ceramicmembranes 150 may be fluidly coupled to a manifold (not shown), and themanifold may be fluidly coupled to the greater-density fluid outlet 124.

For the separator 100, the ceramic membranes 150 may be ultrafiltrationor nanofiltration membranes operable to enable the water andwater-soluble constituents of the intermediate fluid 140 to pass throughceramic membrane 150 from the retentate side 156 to the permeate side158, while reducing or preventing passage of solids through the ceramicmembrane 150. The ceramic membranes 150 may have an average pore sizesufficient to reduce or prevent passage of solid particles through theceramic membranes 150. The ceramic membranes 150 of the separator 100may have an average pore size of less than or equal to 0.5 micrometer(μm), less than 0.25 μm, or even less than or equal to 0.1 μm. Theaverage pore size may be determined through thermoporometry usingdifferential scanning calorimetry (DSC), among other methods. Theceramic membranes 150 of the separator 100 may have an average pore sizeof greater than or equal to 0.005 μm, greater than or equal to 0.01 μm,or even greater than or equal to 0.05 μm. The at least one ceramicmembrane 150 may have an average pore size of from 0.005 μm to 0.5 μm,from 0.005 μm to 0.25 μm, from 0.005 μm to 0.1 μm, from 0.01 μm to 0.5μm, from 0.01 μm to 0.25 μm, from 0.01 μm to 0.1 μm, from 0.05 μm to 0.5μm, from 0.05 μm to 0.25 μm, or from 0.05 μm to 0.1 μm.

Referring to FIG. 1, the ceramic membranes 150 may be operable toseparate the intermediate fluid 140 into a greater-density fluid 106 anda medium-density fluid 108. As the intermediate fluid 140 passes intoand through each of the ceramic membranes 150, at least a portion of theintermediate fluid 140 may permeate into and through the walls of theceramic membrane 150 from the retentate side 156 to the permeate side158. The portion of the intermediate fluid 140 passing through theceramic membrane 150 may pass into the chamber 112 of the separatorcasing 110 as the permeate. The permeate may be the medium-density fluid108. The medium-density fluid 108 may fill the chamber 112 of theseparator casing 110 and may be passed out of the separator casing 110through the permeate outlet 114. The medium-density fluid 108 may besubstantially free of solids. As used in this disclosure, the term“substantially free” of a constituent means less than 1 weight percent(wt. %) of that component in a particular portion of a composition, suchas the multi-phase composition 102, lesser-density fluid 104,greater-density fluid 106, medium density fluid 108, or intermediatefluid 140. As an example, the medium-density fluid 108 that issubstantially free of solids may have less than 1 wt. % solids based onthe total weight of the medium-density fluid 108.

The remaining portions of the intermediate fluid 140, including thegreatest portion of the solids, continue through the cylindrical tubes151 of the ceramic membranes 150 to the retentate outlets 154 of theceramic membranes 150. The remaining portions of the intermediate fluid140 may comprise the greater-density fluid 106. The greater-densityfluid 106 may be passed out of the retentate outlets 154 of the ceramicmembranes 150 and out of the separator 100 through the one or moregreater-density fluid outlets 124. The greater-density fluid 106 mayhave a concentration of solids greater than the concentration of solidsin the intermediate fluid 140 and the medium-density fluid 108.

Referring again to FIG. 1, the separator casing 110 may include one or aplurality of internal walls 116. The internal walls 116 may divide thechamber 112 into a plurality of compartments 118, 120, 122. Each of thecompartments may be fluidly isolated from the other compartments by theinternal walls 116. The separator casing 110 may include 1, 2, 3, 4, ormore than 4 internal walls 116 dividing the chamber 112 into 2, 3, 4, 5,or more than 5 compartments, respectively. In one or more embodiments,the separator casing 110 may include at least one internal wall 116 thatmay divide the chamber 116 into at least a first compartment 118 and asecond compartment 120. The first compartment 118 may be in fluidcommunication with the accepted outlet 136 of the hydrocyclone 130, themembrane inlets 152 of the ceramic membranes 150, or both. The firstcompartment 118 may provide a first flow path for direct fluidcommunication between the accepted outlet 136 of the hydrocyclone 130and the membrane inlets 152 of the ceramic membranes 150. Thus, thefirst flow path provided by the first compartment 118 may fluidly couplethe accepted outlet 136 of the hydrocyclone 130 to the membrane inlets152 of the ceramic membranes 150.

The second compartment 120 may include the permeate outlet 114 and maybe in fluid communication with the permeate side 158 of the ceramicmembrane 150. The second compartment 120 may provide a second flow pathfor direct fluid communication between the permeate sides 158 of theceramic membranes 150 and the permeate outlet 114. Thus, the permeateoutlet 114 of the separator casing 110 may be in fluid communicationwith the permeate sides 158 of the ceramic membranes 150 by way of thesecond flow path in the second compartment 120.

The separator casing 110 may also include a third compartment 122, whichmay be separated from the second compartment 120 by another of theinternal walls 116 of the separator casing 110. The third compartment122 may be in fluid communication with the retentate outlets 154 of eachof the ceramic membranes 150. The third compartment 122 may include thegreater-density fluid outlet 124. The third compartment 122 may providea third flow path for direct fluid communication between the retentateoutlets 154 of the ceramic membranes 150 with the greater-density fluidoutlet 124. Thus, the third flow path provided by the third compartment122 may fluidly couple the retentate outlet 154 of each of the ceramicmembranes 150 with the greater-density fluid outlet 124.

Referring again to FIG. 1, in operation of the separator 100, themulti-phase composition 102 may be introduced to the hydrocyclone 130through the hydrocyclone inlet 132. The hydrocyclone 130 may be operableto produce a cyclonic flow, which may separate the multi-phasecomposition 102 into the lesser-density fluid 104 and an intermediatefluid 140. The lesser-density fluid 104 may be passed out of theseparator 100 through the reject outlet 134 of the hydrocyclone 130. Theintermediate fluid 140 may pass out of the hydrocyclone 130 through theaccepted outlet 136. The intermediate fluid 140 may pass into the firstcompartment 118 and through the first compartment 118 to the membraneinlet 152 of each of the ceramic membranes 150. The intermediate fluid140 may flow through the ceramic membranes 150. A portion of theintermediate fluid 140, such as water and certain aqueous constituents,may pass through the porous walls of the ceramic membranes 150 from theretentate side 156 to the permeate side 158 and into the secondcompartment 120 to produce the medium-density fluid 108. Themedium-density fluid 108 may completely fill the second compartment 120and may be passed out of the separator 100 through the permeate outlet114. The retained portions of the intermediate fluid 140 may continuethrough the cylindrical tubes 151 and may pass out of the ceramicmembranes 150 through the retentate outlets 154 to produce thegreater-density fluid 106. The greater-density fluid 106 may be passedout of the separator 100 through the greater-density fluid outlet 124.

Referring now to FIG. 3, the separator 100 may be incorporated into aseparator system 170. The separator system 170 may include the separator100, which may have any of the features or attributes previouslydescribed in the present disclosure for separator 100. The separatorsystem 170 may include at least one pressure sensor 180, 182, 184, 186,188, at least one control valve 190, 192, 194, at least one processor172 communicatively coupled to the pressure sensor and the controlvalve, and at least one memory module 174 communicatively coupled to theprocessor 172. The separator system 170 may also include a pump 176disposed upstream of the hydrocyclone inlet 132. The pump 176 may beoperable to convey the multi-phase composition 102 to the hydrocycloneinlet 132, increase or decrease a flowrate or pressure of themulti-phase composition 102 at the hydrocyclone inlet 132, or both. Inone or more embodiments, the processor 172 may be communicativelycoupled to the pump 176 or a pump control device coupled to the pump 176to enable control of the pump speed or pumping rate of the pump 176.

The at least one pressure sensor may be operatively coupled to thehydrocyclone inlet 132, the reject outlet 134, the membrane inlets 152of the ceramic membranes 150, the retentate outlets 154 of the ceramicmembranes 150, or the separator casing 110. When used with respect topressure sensors, the term “operatively coupled” may refer to thepressure sensor being positioned relative to a component or structure ofthe separator 100 and configured to measure a pressure of a fluidproximate the component or structure. In one or more embodiments, theseparator system 170 may include a plurality of pressure sensors, suchas a hydrocyclone inlet pressure sensor 180, a lesser-density fluidpressure sensor 182, an intermediate fluid pressure sensor 184, aretentate pressure sensor 186, a permeate pressure sensor 188, orcombinations of these pressure sensors.

The separator system 170 can include the hydrocyclone inlet pressuresensor 180 that may be operatively coupled to the hydrocyclone inlet132. In one or more embodiments, the hydrocyclone inlet pressure sensor180 may be operatively coupled to the cylindrical inlet chamber 144 ofthe hydrocyclone 130 or to a transfer line upstream of the hydrocycloneinlet 132. The hydrocyclone inlet pressure sensor 180 may be operable todetermine the pressure of the multi-phase composition 102 at thehydrocyclone inlet 132 or in the cylindrical inlet chamber 144, such asby measuring a property or force indicative of the pressure. Thehydrocyclone inlet pressure sensor 180 may be operable to transmit asignal indicative of the pressure of the multi-phase composition 102 atthe hydrocyclone inlet 132 or cylindrical inlet chamber 144 to theprocessor 172.

The separator system 170 may include the lesser-density fluid pressuresensor 182 operatively coupled to the reject outlet 134 of thehydrocyclone 130. In one or more embodiments, the lesser-density fluidpressure sensor 182 may be operatively coupled to a transfer line thatis downstream of and in fluid communication with the reject outlet 134of the hydrocyclone 130. The lesser-density fluid pressure sensor 182may be operable to determine a pressure of the lesser-density fluid 104passed out of the hydrocyclone 130 from the reject outlet 134, such asby measuring a property or force indicative of the pressure. Thelesser-density fluid pressure sensor 182 may be operable to transmit asignal indicative of the pressure of the lesser-density fluid 104 at thereject outlet 134 of the hydrocyclone 130 to the processor 172.

The separator system 170 may include the intermediate fluid pressuresensor 184, which may be operable to measure a pressure of theintermediate fluid 140 passed from the accepted outlet 136 of thehydrocyclone 130 to the membrane inlets 152 of the ceramic membranes150. The intermediate fluid pressure sensor 184 may be operativelycoupled to one or more of the first compartment 118, the accepted outlet136 of the hydrocyclone 130, the membrane inlet 152 of at least one ofthe ceramic membranes 150, or combinations of these. In one or moreembodiments, the intermediate fluid pressure sensor 184 may be operableto determine the pressure of the intermediate fluid 140 in the firstcompartment 118 such as by measuring a property or force indicative ofthe pressure. The intermediate fluid pressure sensor 184 may be operableto transmit a signal indicative of the pressure of the intermediatefluid 140 to the processor 172.

The separator system 170 may include the retentate pressure sensor 186,which may be operable to measure a pressure of the greater-density fluid106 passed out of the greater-density fluid outlet 124 of the separator100. The retentate pressure sensor 186 may be operatively coupled to oneor more of the third compartment 122 of the separator casing 110, thegreater-density fluid outlet 124, the retentate outlet 154 of at leastone of the ceramic membranes 150, a transfer pipe or conduit downstreamof the greater-density fluid outlet 124, or combinations of these. Inone or more embodiments, the retentate pressure sensor 186 may beoperable to determine the pressure of the greater-density fluid 106 inthe greater-density fluid outlet 124 of the separator casing 110, suchas by measuring a property or force indicative of the pressure. Theretentate pressure sensor 186 may be operable to transmit a signalindicative of the pressure of the greater-density fluid 106 proximatethe greater-density fluid outlet 124 to the processor 172.

The separator system 170 may include the permeate pressure sensor 188,which may be operable to measure a pressure of the medium-density fluid108 in the second compartment 120 of the separator casing 110 or passedout of the permeate outlet 114 of the separator casing 110. Aspreviously discussed, during operation of separator 100, themedium-density fluid 108 may completely fill the second compartment 120of the separator casing 110. The permeate pressure sensor 188 may beoperatively coupled to one or more of the second compartment 120 of theseparator casing 110, the permeate outlet 114, a transfer linedownstream of the permeate outlet 114, or combinations of these. In oneor more embodiments, the permeate pressure sensor 188 may be operable todetermine the pressure of the medium-density fluid 108 in the secondcompartment 120 of the separator casing 110, the permeate outlet 114, orboth, such as by measuring a property or force indicative of thepressure. The permeate pressure sensor 188 may be operable to transmit asignal indicative of the pressure of the medium-density fluid 108 in thesecond compartment 120, proximate the permeate outlet 114, or both, tothe processor 172.

Each of the hydrocyclone inlet pressure sensor 180, the lesser-densityfluid pressure sensor 182, the intermediate fluid pressure sensor 184,the retentate pressure sensor 186, and the permeate pressure sensor 188may be any commercially-available pressure sensor. The pressure sensorfor one or more of the hydrocyclone inlet pressure sensor 180, thelesser-density fluid pressure sensor 182, the intermediate fluidpressure sensor 184, the retentate pressure sensor 186, and the permeatepressure sensor 188 may be the same or different. Each of thehydrocyclone inlet pressure sensor 180, the lesser-density fluidpressure sensor 182, the intermediate fluid pressure sensor 184, theretentate pressure sensor 186, the permeate pressure sensor 188, orcombinations of these may be communicatively coupled to the processor172.

Referring to FIG. 3, the separator system 170 may further include atleast one control valve operatively coupled to a permeate outlet 114 ofthe separator casing 110, a greater-density fluid outlet 124 of theseparator casing 110, the reject outlet 134 of the hydrocyclone 130, orcombinations of these. When used with respect to control valves, theterm “operatively coupled” may refer to positioning of the control valvein the flow path of a fluid, such as a transfer pipe or conduit throughwhich the fluid flows, so that the control valve can operate to controlthe flowrate of the fluid through the flow path. In one or moreembodiments, the separator system 170 may include a plurality of controlvalves, such as but not limited to a retentate control valve 190, apermeate control valve 192, a lesser-density fluid control valve 194, orcombinations of these. The retentate control valve 190, permeate controlvalve 192, lesser-density fluid control valve 194, or combinations ofthese, may be communicatively coupled to the processor 172.

The retentate control valve 190 may be disposed proximate thegreater-density fluid outlet 124 of the separator 100. The retentatecontrol valve 190 may be fluidly coupled to the greater-density fluidoutlet 124 or disposed in a transfer line or conduit downstream of thegreater-density fluid outlet 124. The retentate control valve 190 may beoperable to receive a signal from the processor 172 indicative of aposition of the retentate control valve 190. In response to the signalreceived from the processor 172, the retentate control valve 190 mayfurther be operable to increase or decrease a flowrate of thegreater-density fluid 106 passing out of the greater-density fluidoutlet 124 of the separator 100.

The permeate control valve 192 may be disposed proximate the permeateoutlet 114 of the separator 100. The permeate control valve 192 may befluidly coupled to the permeate outlet 114 or disposed in a transferline or conduit downstream of the permeate outlet 114. The permeatecontrol valve 192 may be operable to receive a signal from the processor172 indicative of a position of the permeate control valve 192. Inresponse to the signal received from the processor 172, the permeatecontrol valve 192 may be further operable to increase or decrease aflowrate of the medium-density fluid 108 passing out of the permeateoutlet 114.

The lesser-density fluid control valve 194 may be disposed proximate thereject outlet 134 of the hydrocyclone 130. The lesser-density fluidcontrol valve 194 may be fluidly coupled to the reject outlet 134 of thehydrocyclone 130 or disposed in a transfer line or conduit downstream ofthe reject outlet 134. The lesser-density fluid control valve 194 may beoperable to receive a signal from the processor 172 indicative of aposition of the lesser-density fluid control valve 194. In response tothe signal received from the processor 172, the lesser-density fluidcontrol valve 194 may be further operable to increase or decrease aflowrate of the lesser-density fluid 104 passing out of the rejectoutlet 134 of the hydrocyclone 130. Each of the retentate control valve190, the permeate control valve 192, and the lesser-density fluidcontrol valve 194 may be any type of commercially-available controlvalve capable of controlling the flow of a fluid through a conduit orpipe. Increasing or decreasing the flowrate of the lesser-density fluid104, the greater-density fluid 106, the medium-density fluid 108, orcombinations of these may change the pressures at various regions withinthe separator 100.

Referring again to FIG. 3, the at least one processor 172 and at leastone memory module 174 may be part of a computing device 171, throughwhich embodiments of the present disclosure can be implemented, such aspressure differential control or flowrate control of the separator 100.The computing device 171 may additionally include a network interface173 that may be operable to communicatively couple the processor 172 toone or more of the memory modules 174, pressure sensors (hydrocycloneinlet pressure sensor 180, lesser-density fluid pressure sensor 182,intermediate fluid pressure sensor 184, retentate pressure sensor 186,permeate pressure sensor 188), control valves (retentate control valve190, the permeate control valve 192, the lesser-density fluid controlvalve 194), flowrate sensor 196 (FIG. 4), or combinations of these. Asused in the present disclosure, the term “communicatively coupled” mayrefer to two components being arranged, coupled, or configured in amanner that enables the two components to send and receive communicationsignals between the two components and may include wired or wirelesscommunication. The at least one memory module 174 may includemachine-readable instructions stored on the memory module 174 that, whenexecuted by the processor 172, cause the separator system 170 to performone or more actions.

Referring again to FIG. 3, the separator system 170 may be operable tocontrol operation of the separator 100 based on differential pressuresin the hydrocyclone 130, the ceramic membranes 150, or both. Thehydrocyclone 130 in the separator 100 of the present disclosure may be astatic hydrocyclone, meaning that the hydrocyclone is stationary and isnot rotated to generate the cyclonic flow. The separation performance ofa static hydrocyclone, such as hydrocyclone 130, may be influenced by areject ratio, a pressure drop ratio, or both. The reject ratio may bedefined as a ratio of the flowrate of the fluid through the rejectoutlet (reject outlet 134 of the hydrocyclone 130) divided by the inletflowrate to the hydrocyclone (flowrate of the multi-phase composition102 introduced to the hydrocyclone inlet 132 of hydrocyclone 130). Thereject ratio may be expressed as a percentage (percent (%)). For thehydrocyclone 130 of the present disclosure, the reject ratio can bedefined as the flowrate of the lesser-density fluid 104 through thereject outlet 134 of the hydrocyclone 130 divided by the flowrate of themulti-phase composition 102 at the hydrocyclone inlet 132 times 100. Anexpression for the reject ratio for the hydrocyclone 130 of the presentdisclosure is provided in Equation 1 (EQU. 1):

$\begin{matrix}{R_{R} = {\frac{Q_{104}}{Q_{102}} \times 100\%}} & {{EQU}.\mspace{14mu} 1}\end{matrix}$

In EQU. 1, R_(R) is the reject ratio, Q₁₀₂ is the flowrate of themulti-phase composition 102 at the hydrocyclone inlet 132, and Q₁₀₄ isthe flowrate of the lesser-density fluid 104 at the reject outlet 134 ofthe hydrocyclone 130.

The reject ratio R_(R) for the hydrocyclone 130 of the presentdisclosure may be sufficient to separate a majority of the oil dropletsand organic compounds in the multi-phase composition 102 into thelesser-density fluid 104. The reject ratio R_(R) for the hydrocyclone130 may be greater than or equal to 1.0%, greater than or equal to1.25%, or even greater than or equal to 1.5%. The reject ratio R_(R) forthe hydrocyclone 130 may be less than or equal to 10.0%, less than orequal to 5.0%, less than or equal to 3.0%, or even less than or equal to2.5%. The reject ratio R_(R) for the hydrocyclone 130 may be from 1.0%to 10.0%, from 1.0% to 5.0%, from 1.0% to 3.0%, from 1.0% to 2.0%, from1.25% to 10.0%, from 1.25% to 5.0%, from 1.25% to 3.0%, from 1.25% to2%, from 1.5% to 10.0%, from 1.5% to 5.0%, or from 1.5% to 3.0%. In oneor more embodiments, the reject ratio R_(R) for the hydrocyclone 130 maybe from 1.0% to 3.0%, from 1.75% to 2.25%, from 1.9% to 2.1%, or evenabout 2.0%.

The pressure drop ratio of a hydrocyclone may be defined as a ratio ofthe pressure drop between the inlet of the hydrocyclone and the rejectoutlet and the pressure drop between the inlet of the hydrocyclone andthe aqueous outlet. In the hydrocyclone 130 of the present disclosure,the pressure drop ratio may be a ratio of the pressure drop between thehydrocyclone inlet 132 and the reject outlet 134 and the pressure dropbetween the hydrocyclone inlet 132 and the accepted outlet 136 (aqueousoutlet). An expression for the pressure drop ratio for the hydrocyclone130 of the present disclosure is provided in Equation 2 (EQU. 2).

$\begin{matrix}{C = {\frac{{dP}_{104}}{{dP}_{140}} = \frac{P_{IN} - P_{L}}{P_{IN} - P_{OUT}}}} & {{EQU}.\mspace{14mu} 2}\end{matrix}$In EQU. 2, C is the pressure drop ratio, dP₁₀₄ is the differentialpressure for the lesser-density fluid 104 (pressure drop between thehydrocyclone inlet 132 and the reject outlet 134); and dP₁₄₀ is thepressure differential for the intermediate fluid 140 (pressure dropbetween the hydrocyclone inlet 132 and the accepted outlet 136). P_(IN)is the pressure at the hydrocyclone inlet 132 as determined by thehydrocyclone inlet pressure sensor 180. P_(L) is the pressure at thereject outlet 134 as determined by the lesser-density fluid pressuresensor 182. P_(OUT) is the pressure of the intermediate fluid 140 at theaccepted outlet 136 as determined by the intermediate fluid pressuresensor 184.

The pressure drop ratio C and the reject ratio R_(R) may beinterdependent. For example, changing the pressure drop ratio C maychange the pressure P_(L) of the lesser-density fluid 104 passing out ofthe reject outlet 134 of the hydrocyclone 130, which may change theflowrate Qum of the lesser-density fluid 104 out of the hydrocyclone130. Per EQU. 1, changing the flowrate Q₁₀₄ of the lesser-density fluid104 may result in a change in the reject ratio R_(R).

The pressure drop ratio C for the hydrocyclone 130 of the presentdisclosure may be sufficient to separate a majority of the oil dropletsand organic compounds from the multi-phase composition 102 to producethe lesser-density fluid 104. The pressure drop ratio C for thehydrocyclone 130 may be greater than or equal to 1.4, greater than orequal to 1.5, or even greater than or equal to 1.6. The pressure dropratio C for the hydrocyclone 130 may be less than or equal to 2.0, lessthan or equal to 1.9, or even less than or equal to 1.8. The pressuredrop ratio C for the hydrocyclone 130 may be from 1.4 to 2.0, from 1.4to 1.9, from 1.4 to 1.8, from 1.5 to 2.0, from 1.5 to 1.9, from 1.5 to1.8, from 1.6 to 2.0, from 1.6 to 1.9, or from 1.6 to 1.8.

Referring again to FIG. 3, the separator system 170 may also be operableto control operation of the ceramic membranes 150 to separate theintermediate fluid 140 into the greater-density fluid 106 and themedium-density fluid 108 by controlling the pressure drop across theceramic membranes 150. The pressure drop across the ceramic membranes150 may refer to the difference between the pressure at the retentateside 156 and the pressure on the permeate side 158 of the ceramicmembranes 150. For example, increasing the difference between thepressure at the permeate side 158 and the retentate side 156 of theceramic membranes 150 may increase the mass flux of the medium-densityfluid 108 through the ceramic membranes 150. In addition to influencingthe mass flux of the medium-density fluid 108 through the ceramicmembranes 150, the pressure drop across the ceramic membranes 150 mayhave an effect on the hydrodynamic balance of the hydrocyclone 130, suchas by affecting the pressure drop ratio C.

Referring again to FIG. 3, the separator system 170 may be pressure dropratio controlled. In other words, control of the separator 100 by theseparator system 170 may be based on maintaining a target pressure dropratio C across the hydrocyclone 130. To accomplish control of theseparator 100 based on the pressure drop ratio C, the separator system170 may be operable to measure the pressure of one or more of themulti-phase composition 102 at the hydrocyclone inlet 132, thelesser-density fluid 104 at the reject outlet 134 of the hydrocyclone130, the intermediate fluid 140 at the accepted outlet 136 of thehydrocyclone 130, the greater-density fluid 106 at the greater-densityfluid outlet 124 of the separator 100, the medium-density fluid 108 inthe separator casing 110 or at the permeate outlet 114, or combinationsof these, using one or more of the pressure sensors 180, 182, 184, 186,188 previously described in the present disclosure. The separator system170 may be operable to adjust the pressure of the lesser-density fluid104, the greater-density fluid 106, the medium-density fluid 108, theintermediate fluid 140, or combinations of these, using one or more ofthe control valves 190, 192, 194 previously described in the presentdisclosure.

Referring again to FIG. 3, for pressure drop control of the separator100, the pressure drop ratio C of the hydrocyclone 130 may be determinedby determining the pressure P_(IN) of the multi-phase composition 102 atthe hydrocyclone inlet 132 using the hydrocyclone inlet pressure sensor180; the pressure P_(L) of the lesser-density fluid 104 at the rejectoutlet 134 using the lesser-density fluid pressure sensor 182; and thepressure P_(OUT) of the intermediate fluid 140 at the accepted outlet136 using the intermediate fluid pressure sensor 184. The pressure dropratio C may then be calculated from EQU. 2. The pressure drop ratio Cmay be increased or decreased by manipulating the retentate controlvalve 190, the lesser-density fluid control valve 194, or both. Forexample, moving the retentate control valve 190 at the greater-densityoutlet 124 of the separator 100 to a more open or a more closed positionmay decrease or increase, respectively, the pressure of thegreater-density fluid 106 at the greater-density fluid outlet 124, whichmay cause the pressure P_(OUT) of the intermediate fluid 140 at theaccepted outlet 136 of the hydrocyclone 130 to decrease or increase,respectively. Moving the lesser-density fluid control valve 194 at thereject outlet 134 of the separator 100 to a more open or a more closedposition may decrease or increase, respectively, the pressure P_(L) ofthe lesser-density fluid 104 at the reject outlet 134. The pressureP_(IN) of the multi-phase composition 102 at the hydrocyclone inlet 132may be controlled by a pressure controller or in some instances byincreasing or decreasing a pumping rate of the pump 176.

The pressure drop across the ceramic membranes 150 may be determined bymeasuring the pressure P_(OUT) of the intermediate fluid 140 at themembrane inlets 152, the pressure P_(H) of the greater-density fluid 106at the greater-density fluid outlet 124, and the pressure P_(F) of themedium-density fluid 108 at the permeate outlet 114 or in the separatorcasing 110 (in the second compartment 120 of the separator casing 110).The flowrate of the medium-density fluid 108 (permeate) through theceramic membrane 150 from the retentate side 156 to the permeate side158 may be increased or decreased by manipulating the retentate controlvalve 190, the permeate control valve 192, or both. For example, movingthe permeate control valve 192 to a more open or a more closed positionmay decrease or increase, respectively, the pressure P_(F) of themedium-density fluid 108 at the permeate side 158 of the ceramicmembranes 150, which may increase or decrease, respectively, theflowrate of the medium-density fluid 108 through the ceramic membranes150.

Referring to FIG. 3, the processor 172 of the separator system 170 maybe communicatively coupled to at least one of the pressure sensors 180,182, 184, 186, 188 and at least one control valve 190, 192, 194.Communication may be provided by the at least one network interface 173.The processor 172 may be communicatively coupled to the hydrocycloneinlet pressure sensor 180, the lesser-density fluid pressure sensor 182,the intermediate fluid pressure sensor 184, the retentate pressuresensor 186, the permeate pressure sensor 188, or combinations of these.The processor 172 may also be communicatively coupled to the retentatecontrol valve 190, the permeate control valve 192, the lesser-densityfluid control valve 194, or combinations of these.

The at least one memory module 174 may be communicatively coupled to theat least one processor 172. The separator system 170 may further includemachine readable instructions stored on the at least one memory module174. The machine readable instructions, when executed by the at leastone processor 172, may cause the separator system 170 to measure apressure of at least one of the multi-phase composition 102 introducedto the hydrocyclone inlet 132 of the hydrocyclone 130, thelesser-density fluid 104 at the reject outlet 134, the intermediatefluid 140 passed from the accepted outlet 136 of the hydrocyclone 130 tothe membrane inlets 152, the medium-density fluid 108 in the separatorcasing 110, the greater-density fluid 106 at the greater-density fluidoutlet 124 of the separator casing 110, or combinations of these. Themachine readable instructions, when executed by the at least oneprocessor 172, may cause the separator system 170 to control the atleast one control valve, such as one or more of the retentate controlvalve 190, the permeate control valve 192, the lesser-density fluidcontrol valve 194, or combinations of these control valves, based on themeasured pressure. In one or more embodiments, the machine readableinstructions, when executed by the at least one processor 172, mayfurther cause the separator system 170 to compare the measured pressureagainst a target pressure for the multi-phase composition 102 introducedto the hydrocyclone 130, the lesser-density fluid 104 at the rejectoutlet 134, the intermediate fluid 140 passed from the accepted outlet136 of the hydrocyclone 130 to the membrane inlets 152, themedium-density fluid 108 in the separator casing 110, or thegreater-density fluid 106 at the greater-density fluid outlet 124 of theseparator casing 110, respectively. The machine readable instructions,when executed by the processor 172, may cause the separator system 170to control the at least one control valve, such as the retentate controlvalve 190, the permeate control valve 192, the lesser-density fluidcontrol valve 194, or combinations of these, based on the comparison.

Referring now to FIG. 4, the separator system 170 may include a flowratesensor 196. The flowrate sensor 196 may be disposed in thegreater-density fluid outlet 124 of the separator casing 110. In one ormore embodiments, the flowrate sensor 196 may be disposed upstream ofthe retentate control valve 190. The flowrate sensor 196 may be operableto determine a flowrate Q₁₀₆ of the greater-density fluid 106 passingout of the greater-density fluid outlet 124 of the separator 100. Theflowrate sensor 196 may be any type of commercially available deviceoperable to determine the flowrate of a fluid, such as the flowrate of afluid through a pipe or conduit.

Referring again to FIG. 4, in one or more embodiments, the separatorsystem 170 may be flowrate controlled, meaning that the separator system170 may be operable to control operation of the separator 100 based onthe flowrate of one or more of the lesser-density fluid 104, thegreater-density fluid 106, the medium-density fluid 108, the multi-phasecomposition 102 introduced to the separator 100, or combinations ofthese. The separator system 170 may use the flowrate of one or morefluid streams in combination with one or more of the pressure P_(L) ofthe lesser-density fluid 104, the pressure P_(IN) of the multi-phasecomposition 102 introduced to the hydrocyclone inlet 132, the pressureP_(OUT) of the intermediate fluid 140, the pressure P_(F) of themedium-density fluid 108, or the pressure P_(H) of the greater-densityfluid 106 to control operation of the separator 100. In one or moreembodiments, the separator system 170 may be operable to measure theflowrate Q₁₀₆ of the greater-density fluid 106 passing out of thegreater-density fluid outlet 124 of the separator 100. The separatorsystem 170 may be operable to maintain the flowrate Q₁₀₆ of thegreater-density fluid 106 passing out of the separator 100 at a targetflowrate of the greater-density fluid 106 by adjusting the position ofthe retentate control valve 190. The separator system 170 may adjust thepermeate control valve 192, the lesser-density fluid control valve 194,or both, to adjust the pressures of the various fluid streams of theseparator 100 in response to changes in the flowrate Q₁₀₆ of thegreater-density fluid 106.

The separator system 170 may include machine readable instructionsstored on the at least one memory module 174 that, when executed by theprocessor 172, may cause the separator system 170 to measure theflowrate Q₁₀₆ of the greater-density fluid 106 passing out of thegreater-density fluid outlet 124 of the separator casing 110 and controlthe at least one control valve (retentate control valve 190, permeatecontrol valve 192, or lesser-density fluid control valve 194) based onthe measured flowrate Q₁₀₆ of the greater-density fluid 106. In one ormore embodiments, the at least one control valve may be the retentatecontrol valve 190. The machine readable instructions, when executed bythe processor, may further compare the measured flowrate Q₁₀₆ of thegreater-density fluid 106 with the target flowrate of thegreater-density fluid 106 and adjust the retentate control valve 190based on the comparison.

Although the separator system 170 is depicted in FIGS. 3 and 4 asincluding the processor 172 communicatively coupled to various pressuresensors, flowrate sensors, and control valves, it is understood that themethods of pressure drop ratio control or flowrate control of theseparator 100 may be accomplished using any digital or analog techniquesor devices. It is intended for the methods of the present disclosure toinclude implementation of method steps using either digital or analogtechnologies.

Referring again to FIG. 4, operation of the separator 100 may becontrolled by the separator system 170 through a combination of pressuredrop control and flowrate control. For example, the separator system 170may control operation of the separator 100 by determining the flowrateQ₁₀₆ of the greater-density fluid 106 in combination with the pressuredrop ratio C of the hydroclyclone 130, the pressure differential acrossthe ceramic membranes 150, or both. The determined values for theflowrate Q₁₀₆ of the greater-density fluid 106, the pressure drop ratioC of the hydrocyclones 130, the pressure differential across the ceramicmembranes 150, or combinations of these can be used by the processor 172of the computing device 171 to adjust one or more of the pressures inthe separator 100 to control operation of the separator 100.

Referring again to FIG. 3, a method of separating the multi-phasecomposition 102 having an aqueous phase, an oleaginous phase, and asolid phase may include passing the multi-phase composition 102 to theseparator 100, which may have any of the features or characteristicspreviously described in this disclosure for separator 100. The separator100 may be operable to separate the multi-phase composition 102 into thelesser-density fluid 104, the medium-density fluid 108, and thegreater-density fluid 106. The method may further include collecting thelesser-density fluid 104 from the reject outlet 134 of the hydrocyclone130, collecting the greater-density fluid 106 from the greater-densityfluid outlet 124 of the separator casing 110, and collecting themedium-density fluid 108 from the permeate outlet 114 of the separatorcasing 110.

The method may further include measuring a pressure of at least one ofthe following: the multi-phase composition 102 at the hydrocycloneinlets 132 (pressure P_(IN)); the lesser-density fluid 104 at theaccepted outlet 132 of the hydrocyclones 130 (pressure P_(L)); theintermediate fluid 140 passed from the accepted outlet 136 of thehydrocyclones 130 to the membrane inlets 152 (pressure P_(OUT)); themedium-density fluid 108 in the separator casing 110 or at the permeateoutlet 114 (pressure P_(F)); the greater-density fluid 106 at thegreater-density fluid outlet 124 of the separator casing 110 (pressureP_(H)); or combinations of these. The method may further includeadjusting a position of the retentate control valve 190 at thegreater-density fluid outlet 124, the permeate control valve 192 at thepermeate outlet 114, the lesser-density fluid control valve 194 at thereject outlet 134 of the hydrocyclones 130, or combinations of these,based on the measured pressure. As previously discussed, adjusting theposition of one or more of the retentate control valve 190, the permeatecontrol valve 192, or the lesser-density fluid control valve 194 mayincrease or decrease the pressure of one or more of the multi-phasecomposition 102, the lesser-density fluid 104, the intermediate fluid140, the greater-density fluid 106, the medium-density fluid 108, orcombinations of these. The method may further include comparing themeasured pressure against a target pressure and adjusting the positionof the retentate control valve 190 at the greater-density fluid outlet124, the permeate control valve 192 at the permeate outlet 114, thelesser-density fluid control valve 194 at the reject outlets 134 of thehydrocyclones 130, or combinations of these, based on the comparison.

The method may include measuring the flowrate Q₁₀₆ of thegreater-density fluid 106 passing out of the greater-density fluidoutlet 124 of the separator casing 110 and increasing or decreasing theflowrate Q₁₀₆ of the greater-density fluid 106 from the greater-densityfluid outlet 124 based on the measured pressure. The method may furtherinclude adjusting the position of the permeate control valve 192 at thepermeate outlet 114, a lesser-density fluid control valve 194 at thereject outlet 134 of the hydrocyclone 130, or both, in response toincreasing or decreasing the flowrate Q₁₀₆ of the greater-density fluid106 from the greater-density fluid outlet 124. Adjusting the position ofthe permeate control valve 192 or the lesser-density fluid control valve194 may increase or decrease the pressures of one or more of themulti-phase composition 102, the lesser-density fluid 104, theintermediate fluid 140, the greater density fluid 106, themedium-density fluid 108, or combinations of these.

Referring now to FIG. 5, another embodiment of the separators of thepresent disclosure is depicted, and will be referred to in the presentdisclosure with reference number 200. Separator 200 may include aseparator housing 210 and one or a plurality of hydrocyclones 230disposed within the separator casing 210. The separator casing 210 maydefine a chamber 212 and may include a permeate outlet 214. Thehydrocyclone 230 or plurality of hydrocyclones 230 may be disposedwithin the chamber 212 defined by the separator casing 210. Thehydrocyclones 230 may include a ceramic membrane 250 disposed in atleast a portion of a tapered section 238 of the hydrocyclones 230.

As previously discussed in relation to hydrocyclone 130, thehydrocyclone 230 of separator 200 may be a mechanical device operable toseparate lesser-density constituents of the multi-phase composition 102,such as but not limited to oil droplets and organic compounds, from thegreater-density constituents of the multi-phase composition 102, such assolids, water, or water soluble constituents. The multi-phasecomposition 102 may have any of the features, constituents, orcharacteristics previously described in the present disclosure.

The hydrocyclone 230 may operate by producing a cyclonic flow thatcreates centrifugal forces, which may cause the greater-densityconstituents of the multi-phase composition 102 to move radially outwardfrom a center axis A of the hydrocyclone 230 towards the walls 242 ofthe hydrocyclone 230. The hydrocyclone 230 may include a hydrocycloneinlet 232, a cylindrical inlet chamber 244, the tapered section 238downstream of the cylindrical inlet chamber 244, a reject outlet 234,and an accepted outlet 236. The tapered section 238 may be disposedbetween the reject outlet 234 and the accepted outlet 236. The taperedsection 238 may be frusto-conical in shape having a wide end and anarrow end, where the wide end has a greater diameter than the narrowend. The wide end may be disposed at an upstream end of the taperedsection 238, and the narrow end may be disposed downstream of the wideend of the tapered section 238. The wide end of the tapered section 238may be coupled to the cylindrical inlet chamber 244. The tapered section238 may be defined by a cone angle α and a length LT of the taperedsection 238. The cone angle α, length LT of the tapered section 238, andoverall length L of the hydrocyclone 230 may be selected based on thecharacteristics of the multi-phase composition 102. The tapered section238 may be centered about the center axis A of the hydrocyclone 230.

The reject ratio R_(R) for the hydrocyclone 230 of the separator 200 maybe sufficient to separate a majority of the oil droplets and organiccompounds in the multi-phase composition 102 into the lesser-densityfluid 104. The reject ratio R_(R) for the hydrocyclone 230 may begreater than or equal to 1.0%, greater than or equal to 1.25%, or evengreater than or equal to 1.5%. The reject ratio R_(R) for thehydrocyclone 230 may be less than or equal to 5.0%, less than or equalto 3.0%, or even less than or equal to 2.5%. For reject ration R_(R)greater than 5.0%, the flowrate across the ceramic membrane 250 of thetapered section may be reduced, which may decrease the effectiveness ofthe ceramic membrane 250 for separating the solids. The reject ratioR_(R) for the hydrocyclone 130 may be from 1.0% to 5.0%, from 1.0% to3.0%, from 1.0% to 2.0%, from 1.25% to 5.0%, from 1.25% to 3.0%, from1.25% to 2%, from 1.5% to 5.0%, or from 1.5% to 3.0%. In one or moreembodiments, the reject ratio R_(R) for the hydrocyclone 230 may be from1.0% to 3.0%, from 1.75% to 2.25%, from 1.9% to 2.1%, or even about2.0%.

The hydrocyclone inlet 232 may be coupled to the cylindrical inletchamber 244 and may be configured to introduce the multi-phasecomposition 102 to the hydrocyclone 230 in a manner that creates acyclonic flow in the hydrocyclone 230. The hydrocyclone inlet 232 may betangent to the inner cylindrical surface of the cylindrical inletchamber 244. In one or more embodiments, the hydrocyclone inlet 232 maybe coupled to the cylindrical inlet chamber 244 so that the hydrocycloneinlet 232 may be parallel with a plane tangent to the cylindrical inletchamber 244.

The reject outlet 234 of the hydrocyclone 230 may be in fluidcommunication with the cylindrical inlet chamber 244 of the hydrocyclone230 and may be aligned with the center axis A of the hydrocyclone 230.The reject outlet 234 may be coupled to the cylindrical inlet chamber244 at an end opposite the tapered section 238. The reject outlet 234may include an open-ended conduit that extends at least partially intothe cylindrical inlet chamber 244. The open-ended conduit may beoperable to reduce or prevent the multi-phase composition 102 introducedto the hydrocyclone 230 from flowing directly into the reject outlet 234without being subjected to the cyclonic flow within the hydrocyclone230. The accepted outlet 236 of the hydrocyclone 230 may be positioneddownstream of the narrow end of tapered section 238. In other words,accepted outlet 236 of the hydrocyclone 230 may be positioned at adownstream end of the tapered section 238 relative to the upstream endcoupled to the cylindrical inlet chamber 244. The accepted outlet 236may be aligned with the center axis A of the hydrocyclone 230. In someembodiments, the accepted outlet 236 of the hydrocyclone 230 may extendthrough the separator casing 210 to provide a medium-density fluidoutlet 224 of the separator 200. The medium-density fluid outlet 224 maybe an outlet from which the medium-density fluid 108 passes out of theseparator 200.

The tapered section 238 may include the ceramic membrane 250. Theceramic membrane 250 may form at least a portion of the tapered section238 of the hydrocyclone 230. The ceramic membrane 250 may extenddownstream of the narrow end of the tapered section 238 of thehydrocyclone 230 in the direction of the accepted outlet 236. Theceramic membrane 250 may have a retentate side 256 oriented toward aninterior of the hydrocyclone 230, such as inward towards the center axisA, and a permeate side 258 in fluid communication with the chamber 212defined by the separator casing 210. At least a portion of the retentateside 256 of the ceramic membrane 250 may have a frusto-conical shape.The ceramic membrane 250 may have a frusto-conical portion and acylindrical portion, where in the frusto-conical portion, the retentateside 256 has a frusto-conical shape and, in the cylindrical portion, theretentate side 256 may have a cylindrical shape. The cylindrical portionmay extend downstream of the tapered section 238 of the hydrocyclone230. The frusto-conical shape of the portion of the retentate side 256of the ceramic membrane 250 may contribute to maintain the cyclonicfluid flow through the cavity defined by the walls 242 of the ceramicmembrane 250. The continued cyclonic or vortex fluid flow in the taperedsection 238 having the ceramic membrane 250 may maintain movement of thefluids near the retentate side 256 of the ceramic membrane 250, whichmay operate to reduce bio-fouling of the ceramic membrane 250. Thus, thevortex flow in the tapered section 258 of the hydrocyclone 230 mayreduce or prevent bio-fouling of the retentate side 256 of the ceramicmembrane 250 in the tapered section 258.

The retentate side 256 of the ceramic membrane 250 may be flush with thewalls 242 of the hydrocyclone 230 at the upstream and downstream ends ofthe ceramic membrane 250. The frusto-conical shape of the ceramicmembrane 250 may enable the hydrocyclone 230 to be operable to produce acyclonic fluid flow in the multi-phase composition 102 introduced to thehydrocyclone 230. The permeate side 258 of the ceramic membrane 250 maybe in fluid communication with the chamber 212 defined by the separatorcasing 210 and the permeate outlet 214 of the separator casing 210.

Referring to FIG. 6, a portion of the hydrocyclone 230 of separator 200is depicted showing an embodiment of a ceramic membrane assembly 260 forincorporating the ceramic membrane 250 into the hydrocyclone 230. Theceramic membrane assembly 260 may include a membrane housing 262defining an internal chamber 263 having a diameter at a downstream end253 sufficient to center the downstream end 253 of the ceramic membrane250 and ensure that the downstream end 253 of the ceramic membrane 250is positioned accurately on the seal arrangement 264. The ceramicmembrane 250 may be disposed within the internal chamber 263 of themembrane housing 262 with a downstream end of the ceramic membrane 250seated against the seal arrangement 264. The membrane housing 262 mayinclude a plurality of openings 265, such as slots, holes, orperforations, that may enable fluid communication between the permeateside 258 of the ceramic membrane and the chamber 212 defined by theseparator casing 210. Arrows 269 in FIG. 6 indicate the permeate passingfrom the permeate side 258 of the ceramic membrane 250 through theopenings 265 to the chamber 212 of the separator casing 210.

Referring again to FIG. 6, the ceramic membrane assembly 260 may includea centering flange 266 disposed at the upstream end of the ceramicmembrane 250. The centering flange 266 may be operable to position theceramic membrane 250 within the membrane housing 262 so that theretentate side 256 of the ceramic membrane 250 is flush with the walls242 of the hydrocyclone 230. The centering flange 266 may include afrusto-conical opening 267 providing a transitional surface between theceramic membrane 250 and a head 268 of the hydrocyclone 230. The head268 of the hydrocyclone 230 may be coupled to the membrane housing 262to secure the ceramic membrane 250 within the membrane housing 262. Theceramic membrane assembly 260 may include seals 264 at either end of theceramic membrane 250. The seals 264 may be operable to reduce or preventfluid flow between the retentate side 256 and permeate side 258 of theceramic membrane 250 without passing through the ceramic membrane 250.FIG. 6 shows one embodiment of a ceramic membrane assembly 260. However,it is understood that methods or mechanical arrangements other than theone shown in FIG. 6 may be employed to secure the ceramic membrane 250in the hydrocyclone 230.

For separator 200, the ceramic membrane 250 may be a particle filtrationmembrane having an average pore size sufficient to enable suspendedsolid particles from the multi-phase composition 102 to pass through theceramic membrane 250. The ceramic membranes 250 of the separator 200 mayhave an average pore size of greater than or equal to 0.25 μm, greaterthan or equal to 0.5 μm, greater than or equal to 0.75 μm, or greaterthan or equal to 1.0 μm. The ceramic membrane 250 of the separator 200may have an average pore size of less than or equal to 25 μm, less thanor equal to 20 μm, or less than or equal to 15 μm. The ceramic membrane250 of separator 200 may have an average pore size of from 0.25 μm to 25μm, from 0.25 μm to 20 μm, from 0.25 μm to 15 μm, from 0.5 μm to 25 μm,from 0.5 μm to 20 μm, from 0.5 μm to 15 μm, from 0.75 μm to 25 μm, from0.75 μm to 20 μm, 0.75 μm to 15 μm, from 1.0 μm to 25 μm, from 1.0 μm to20 μm, or from 1.0 μm to 15 μm.

The separator 200 may be operable to separate the multi-phasecomposition 102 into the lesser-density fluid 104, the greater-densityfluid 106, and the medium-density fluid 108. The lesser-density fluid104 may be passed out of the reject outlet 234 of the hydrocyclone 230,the medium-density fluid 108 may be passed out of the accepted outlet236 of the hydrocyclone 230, and the greater-density fluid 106 may passthrough the ceramic membrane 250 into the chamber 212 defined by theseparator casing 210.

For ease of illustration and description, the separator 200 is describedin the context of having a single hydrocyclone 230. However, it isunderstood that any of the separators 200 and separator systems 270 ofthe present disclosure may have a plurality of hydrocyclones 230disposed within the separator casing 210. Referring now to FIG. 14, theseparator 200 may have a plurality of hydrocyclones 230, such as 2, 3,4, 5, 6, or more than 6 hydrocyclones 230 disposed within the separatorcasing. Such a layout may enable a number of hydrocyclones 230 tooperate in parallel under the same process conditions, thus, increasingthe flow capacity of the separator 200 while reducing the spatialfootprint and the costs associated with manufacturing and siteinstallation. In one or more embodiments, the separators 200 may includeup to several dozen hydrocyclones 230 disposed with the separator casing210.

Referring again to FIG. 5, in operation of the separator 200, themulti-phase composition 102 may be introduced to the hydrocyclone 230through the hydrocyclone inlet 232. The hydrocyclone 230 may be operableto produce a cyclonic or vortex flow within the hydrocyclone 230. Thecentrifugal forces produced in the tapered section 238 of thehydrocyclone 230 may cause the greater-density constituents, such assuspended solid particles and aqueous constituents, of the multi-phasecomposition 102 to migrate radially outward towards the walls 242 of thehydrocyclone 230. The cyclonic flow may cause the lesser-densityconstituents, such as oil droplets and other organic components, tomigrate toward the center axis A of the hydrocyclone 230. Thelesser-density constituents may form a secondary vortex, which mayconvey the lesser-density constituents towards the reject outlet 234 ofthe hydrocyclone 230 (in the +X direction of the coordinate axis in FIG.5). The lesser-density fluid 104 may be passed out of the separator 200by way of the reject outlet 234 of the hydrocyclone 230. Thelesser-density fluid 104 may have a greater concentration of oildroplets, organic compounds, or both, compared to the multi-phasecomposition 102. The lesser-density fluid 104 may have a decreasedconcentration of suspended solids and aqueous constituents compared tothe multi-phase composition 102.

The cyclonic flow may cause suspended solid particles to concentratealong the walls 242 of the hydrocyclone 230. The ceramic membrane 250may be disposed in at least a downstream portion of the tapered section238. The ceramic membrane 250 may have a porosity that enables suspendedsolids from multi-phase composition 102 to pass through the ceramicmembrane 250 into the chamber 212. When the solids concentrated at thewall 242 reach the ceramic membrane 250, the average pore size of theceramic membrane 250 may allow the solid particles to pass through theceramic membrane 250 from the retentate side 256 to the permeate side258 and into the chamber 212. At least a portion of the water and othergreater-density constituents may also pass through the ceramic membrane250. Migration of the solid particles through the ceramic membrane 250may provide a partial blocking effect, which may reduce the flowrate ofwater and other greater-density constituents through the ceramicmembrane 250. Thus, the permeate passing through the ceramic membrane250 may be the greater-density fluid 106 having a greater concentrationof solid particles compared to the multi-phase composition 102introduced to the separator 200. The greater-density fluid 106 passingthrough the ceramic membrane 250 may completely fill the chamber 212defined by the separator casing 210. The greater-density fluid 106 maybe passed out of the chamber 212 and out of the separator 200 throughthe permeate outlet 214.

The remaining aqueous constituents of the multi-phase composition 102may continue in cyclonic flow through the hydrocyclone 230 to theaccepted outlet 236 of the hydrocyclone 230. The fluid exiting theaccepted outlet 236 of the hydrocyclone 230 downstream of the ceramicmembrane 250 may be the medium-density fluid 108. The medium-densityfluid 108 may have a concentration of solid particles less than theconcentration of solid particles in the greater-density fluid 106passing through the ceramic membrane 250. The medium-density fluid 108may also have a concentration of oil droplets and other organiccompounds less than the concentration of oil droplets and organiccompounds in the lesser-density fluid 104. In some embodiments, theaccepted outlet 236 of the hydrocyclone 230 may extend through theseparator casing 210 such that the accepted outlet 236 comprises themedium-density fluid outlet 224 of the separator 200. The medium-densityfluid 108 may be passed out of the separator 200 through themedium-density fluid outlet 224.

Referring now to FIG. 7, the separator 200 may include a separatorcasing 210 having one or more internal walls, such as internal wall 216,that divide the chamber 212 into a plurality of compartments. Theseparator casing 210 may include 1, 2, 3, or more than 3 internal walls216 that may separate the chamber 212 into 2, 3, 4, or more than 4compartments. Each of the compartments may be fluidly isolated from theother compartments by the internal walls. In one or more embodiments,the separator casing 210 may include the internal wall 216 dividing thechamber 212 into a first compartment 218 and a second compartment 220.The first compartment 218 may be in fluid communication with thepermeate side 258 of the ceramic membrane 250 and with the permeateoutlet 214 of the separator casing 210. The second compartment 220 maybe in fluid communication with the accepted outlet 236 of thehydrocyclone 230. The second compartment 220 may include amedium-density fluid outlet 224. The second compartment 220 may providea flow path between the accepted outlet 236 of the hydrocyclone 230 andthe medium-density fluid outlet 224.

In operation, the greater-density fluid 106 may pass through the ceramicmembrane 250 into the first compartment 218. At start-up, the firstcompartment 218 may accumulate the greater-density fluid 106 until thefirst compartment 218 is full of the greater-density fluid 106. Duringsteady state operation of the separator 200, the first compartment 218may be full of the greater-density fluid 106. The greater-density fluid106 may pass out of the first compartment 218 through the permeateoutlet 214. The medium-density fluid 108 may pass out of the acceptedoutlet 236 of the hydrocyclone 230 into the second compartment 220. Themedium-density fluid 108 may accumulate in the second compartment 220,completely filling the second compartment 220, and may pass out of thesecond compartment 220 through the medium-density fluid outlet 224.

In some embodiments, the internal wall 216 of the separator casing 210may be a flexible membrane or wall that may be operable to equalize thepressure between the first compartment 218 and the second compartment220. For example, the internal wall 216 may be flexible so that thepressure P_(F) of the greater-density fluid 106 in the first compartment218 can be passively controlled to be equal to the pressure P_(OUT) ofthe medium-density fluid 108 in the second compartment 220. Thus, thepresence of flexible internal walls 216 in the separator casing 210 mayenable passive pressure control operation of the separator 200.

Referring now to FIG. 8A, a separator system 270 that includes theseparator 200 is depicted. The separator 200 may have any of thefeatures, characteristics, or attributes previously described in thepresent disclosure for separator 200. The separator system 270 mayinclude at least one pressure sensor, such as a medium-density fluidpressure sensor 282, a greater-density fluid pressure sensor 284, otherpressure sensor, or combinations of pressure sensors. The separatorsystem 270 may also include at least one control valve, such as amedium-density fluid control valve 290. The separator system 270 mayalso include the at least one processor 172 communicatively coupled tothe at least one pressure sensor and the control valve. The separatorsystem 270 may further include the at least one memory module 174communicatively coupled to the processor 172. The separator system 270may additionally include a pump 176 disposed upstream of thehydrocyclone inlet 232. The pump 176 may be operable to convey themulti-phase composition 102 to the hydrocyclone inlet 232. The pump 176may also be operable to increase or decrease a flowrate or pressure ofthe multi-phase composition 102 at the hydrocyclone inlet 232. In one ormore embodiments, the processor 172 may be communicatively coupled tothe pump 176 or a pump control device attached to the pump 176 to enablecontrol of the pump speed or pumping rate of the pump 176.

The at least one pressure sensor may be operatively coupled to theaccepted outlet 236 of the hydrocyclone 230, the medium-density fluidoutlet 224 of the separator casing 210, the chamber 212 of the separatorcasing 210, or the permeate outlet 214 of the separator casing 210. Inone or more embodiments, the separator system 270 may include aplurality of pressure sensors, such as a medium-density fluid pressuresensor 282, a greater-density fluid pressure sensor 284, other pressuresensor, or combinations of pressure sensors. The medium-density fluidpressure sensor 282, the greater-density fluid pressure sensor 284, orboth, may be any commercially-available pressure sensor. Themedium-density fluid pressure sensor 282 and the greater-density fluidpressure sensor 284 may be the same or different. The medium-densityfluid pressure sensor 282, the greater-density fluid pressure sensor284, or both, may be communicatively coupled to the processor 172.

The separator system 270 may include the medium-density fluid pressuresensor 282, which may be operatively coupled to the accepted outlet 236of the hydrocyclone 230, the medium-density fluid outlet 224 of theseparator casing 210, a transfer line downstream of the medium-densityfluid outlet 224 or accepted outlet 236, or combinations of these. Themedium-density fluid pressure sensor 282 may be operable to determinethe pressure P_(OUT) of the medium-density fluid 108 passed out of theaccepted outlet 236 of the hydrocyclone 230 or out of the medium-densityfluid outlet 224 of the separator casing 210, such as by measuring aforce or property indicative of the pressure P_(OUT). In one or moreembodiments, the medium-density fluid pressure sensor 282 may beoperable to transmit a signal indicative of the pressure P_(OUT) of themedium-density fluid 108 to the processor 172.

The separator system 270 may include the greater-density fluid pressuresensor 284. The greater-density fluid pressure sensor 284 may beoperatively coupled to one or more of the separator casing 210, thepermeate outlet 214, a transfer line downstream of the permeate outlet214, or combinations of these. In one or more embodiments, thegreater-density fluid pressure sensor 284 may be operatively coupled tothe separator casing 210 in fluid communication with the permeate side258 of the ceramic membrane 250. The greater-density fluid pressuresensor 284 may be operable to determine the pressure P_(F) of thegreater-density fluid 106 in the separator casing 210, the permeateoutlet 214, or both, such as by measuring a force or property indicativeof the pressure P_(F). The greater-density fluid pressure sensor 284 maybe operable to transmit a signal indicative of the pressure P_(F) of thegreater-density fluid 106 in the separator casing 210 or at the permeateoutlet 214 to the processor 172.

Although the separator system 270 is depicted in FIG. 8A as includingthe processor 172, medium-density fluid pressure sensor 282, andgreater-density fluid pressure sensor 284 communicatively coupledtogether, it is understood that the processor 172, medium-density fluidpressure sensor 282, and greater-density fluid pressure sensor 284 canbe integrated into a single device, such as a digital or analog pressurecontroller that may be operatively coupled to the medium-density fluidcontrol valve 290. It is intended for the present disclosure to includeimplementation of method steps using either digital or analog techniquesand devices.

Referring again to FIG. 8A, the separator system 270 may further includea medium-density fluid control valve 290 operatively coupled to themedium-density fluid outlet 224 of the separator casing 210 or to atransfer pipe or conduit downstream of the medium-density fluid outlet224 of the separator 200. The medium-density fluid control valve 290 maybe communicatively coupled to the processor 172. The medium-densityfluid control valve 290 may be operable to receive a signal from theprocessor 172 indicative of a position of the medium-density fluidcontrol valve 290. In response to the signal received from the processor172, the medium-density fluid control valve 290 may further be operableto move to a more open or more closed position to increase or decrease,respectively, a flowrate of the medium-density fluid 108 passing out ofthe medium-density fluid outlet 224 of the separator 200. Themedium-density fluid control valve 290 may be any type ofcommercially-available control valve capable of controlling the flow ofa fluid through a conduit or pipe.

Referring again to FIG. 8A, the at least one processor 172 and at leastone memory module 174 may be part of the computing device 171, throughwhich embodiments of the present disclosure can be implemented, such aspressure differential control or flowrate control of the separator 200.The computing device 171 may additionally include the network interface173 operable to communicatively couple the processor 172 to one or moreof the memory modules 174, pressure sensors (medium-density fluidpressure sensor 282, the greater-density fluid pressure sensor 284),control valves (medium-density fluid control valve 290), greater-densityfluid flowrate sensor 296 (FIG. 9), or combinations of these. The atleast one memory module 174 may include machine-readable instructionsstored on the memory module 174 that, when executed by the processor172, may cause the separator system 270 to perform one or more actions.

Referring again to FIG. 8A, the separator system 270 may be operable tocontrol operation of the separator 200 based on the differentialpressure between the separator casing 210 and the medium-density fluidoutlet 224. The hydrocyclone 230 of the separator 200 may be a statichydrocyclone, meaning that the hydrocyclone is stationary and is notrotated to generate the cyclonic flow. As previously discussed, theseparation performance of a static hydrocyclone, such as hydrocyclone230, may be influenced by the reject ratio, the pressure drop ratio, orboth. However, the greater average pore size and porosity of the ceramicmembrane 250 integrated into the tapered section 238 of the hydrocyclone230 may enable the hydrocyclone 230 of separator 200 to be modeled as adivision of flow in which the flowrate Q₁₀₂ of the multi-phasecomposition 102 is equal to the sum of the flowrate Q₁₀₄ of thelesser-density fluid 104, the flowrate Q₁₀₆ of the greater-density fluid106, and the flowrate Q₁₀₈ of the medium-density fluid 108.

Referring again to FIG. 8A, operation of the separator system 270 may becontrolled based on the differential pressure across the ceramicmembrane 250. The differential pressure across the ceramic membrane 250may be proportional to a difference between the pressure P_(OUT) of themedium-density fluid 108 at the accepted outlet 236 of the hydrocyclone230 and the pressure P_(F) of the greater-density fluid 106 in theseparator casing 210. To control the separator 200 based on thedifferential pressure between the medium-density fluid 108 and thegreater density fluid 106, the separator system 270 may be operable todetermine the pressure P_(OUT) of the medium-density fluid 108 at theaccepted outlet 236 of the hydrocyclone 230, the pressure P_(F) of thegreater-density fluid 106 in the separator casing 210, or both, usingthe medium-density fluid pressure sensor 282 and the greater-densityfluid pressure sensor 284, respectively. The separator system 270 may beoperable to increase or decrease the pressure P_(OUT) of themedium-density fluid 108 at the accepted outlet 236 of the hydrocyclone230 by adjusting the position of the medium-density fluid control valve290. For example, the pressure P_(OUT) of the medium-density fluid 108at the accepted outlet 236 may be increased by adjusting themedium-density fluid control valve 290 to a more closed position anddecreased by adjusting the medium-density fluid control valve 290 to amore open position.

Referring now to FIG. 8B, the separator system 270 may further include ahydrocyclone inlet pressure sensor 280 and a greater-density fluidcontrol valve 292. The separator system 270 may also optionally includea lesser-density fluid control valve 294. The hydrocyclone inletpressure sensor 280 may be operatively coupled to the hydrocyclone inlet232 of the hydrocyclone 230 or to the cylindrical inlet chamber 244. Thehydrocyclone inlet pressure sensor 280 may be any commercially-availablepressure sensor. The hydrocyclone inlet pressure sensor 280 may becommunicatively coupled to the processor 172. The hydrocyclone inletpressure sensor 280 may be operable to determine the pressure P_(IN) ofthe multi-phase composition 102 introduced to the hydrocyclone 230, suchas by measuring a force or property indicative of the pressure P_(IN).The hydrocyclone inlet pressure sensor 280 may be operable to transmit asignal indicative of the pressure P_(IN) to the processor 172.

The greater-density fluid control valve 292 may be operatively coupledto the permeate outlet 214 of the separator casing 210 or to a conduitor pipe downstream of the permeate outlet 214. The greater-density fluidcontrol valve 292 may be communicatively coupled to the processor 172.The greater-density fluid control valve 292 may be operable to receive asignal from the processor 172 indicative of a position of thegreater-density fluid control valve 292. In response to the signalreceived from the processor 172, the greater-density fluid control valve292 may be further operable to move to a more open or more closedposition to increase or decrease a flowrate of the greater-density fluid106 passing out of the permeate outlet 214 of the separator casing 210.

The lesser-density fluid control valve 294 may be operatively coupled tothe reject outlet 234 or to a conduit or pipe downstream of the rejectoutlet 234 of the hydrocyclone 230. The lesser-density fluid controlvalve 294 may be communicatively coupled to the processor 172. Thelesser-density fluid control valve 294 may be operable to receive asignal from the processor 172 indicative of a position of thelesser-density fluid control valve 294. In response to the signalreceived from the processor 172, the lesser-density fluid control valve294 may be further operable to move to a more open or more closedposition to increase or decrease a flowrate of the lesser-density fluid104 passing out of the reject outlet 234 of the hydrocyclone 230. Thegreater-density fluid control valve 292 and the lesser-density fluidcontrol valve 294 may be any type of commercially-available controlvalve capable of controlling the flow of a fluid through a conduit orpipe.

Referring again to FIG. 8B, the network interface 173 of the computingdevice 171 may be operable to communicatively couple the processor 172to one or more of the memory modules 174, pressure sensors(medium-density fluid pressure sensor 282, the greater-density fluidpressure sensor 284, the hydrocyclone inlet pressure sensor 280),control valves (medium-density fluid control valve 290, greater-densityfluid control valve 292, lesser-density fluid control valve 294),greater-density fluid flowrate sensor 296 (FIG. 9), or combinations ofthese. The separator system 270 may be operable to further controloperation of the separator 200 based on the measured P_(IN) of themulti-phase composition 102 introduced to the hydrocyclone 230 inaddition to the pressure of the medium-density fluid 108 at the acceptedoutlet 236 of the hydrocyclone 230 (P_(OUT)), the greater-density fluid106 in the separator casing 210 or at the permeate outlet 214 of theseparator casing 210 (P_(F)), or both. The inlet pressure P_(IN) of themulti-phase composition 102 may be modified by increasing or decreasingflow of fluids through the medium-density fluid control valve 290, thegreater-density fluid control valve 292, the lesser-density fluidcontrol valve 294, or combinations of these. The separator system 270 ofFIG. 8B may be operable to control the separator 200 based on thepressure drop ratio C of the hydrocyclone 130 in addition to controllingthe separator 200 based on the pressure differential between theseparator casing 210 and the medium-density fluid outlet 224 (pressuredrop across the ceramic membrane 250).

Referring to FIG. 8B, the processor 172 of the separator system 270 maybe communicatively coupled to the hydrocyclone inlet pressure sensor280, the medium-density fluid pressure sensor 282, the greater-densityfluid pressure sensor 284, the medium-density fluid control valve 290,the greater-density fluid control valve 292, the lesser-density fluidcontrol valve 294, or combinations of these. Communication may beprovided by the at least one network interface 173. The at least onememory module 174 may be communicatively coupled to the at least oneprocessor 172. The separator system 270 may further include machinereadable instructions stored on the at least one memory module 174. Themachine readable instructions, when executed by the at least oneprocessor 172, may cause the separator system 270 to measure thepressure of the medium-density fluid 108 at the accepted outlet 236 ofthe hydrocyclone 230 (P_(OUT)), the greater-density fluid 106 in theseparator casing 210 or at the permeate outlet 214 of the separatorcasing 210 (P_(F)), the pressure of the multi-phase composition 102introduced to the hydrocyclone 230 (P_(IN)), or combinations of these.The machine readable instructions, when executed by the at least oneprocessor 172, may cause the separator system 270 to control the atleast one control valve, such as the medium-density fluid control valve290, greater-density control valve 292, lesser-density control valve294, or combinations of these, based on the measured pressure orpressures. In one or more embodiments, the machine readableinstructions, when executed by the at least one processor 172, mayfurther cause the separator system 270 to compare the measured pressureor pressures against a target pressure for the medium-density fluid 108at the accepted outlet 236 of the hydrocyclone 230 (P_(OUT)), thegreater-density fluid 106 in the separator casing 210 or at the permeateoutlet 214 of the separator casing 210 (P_(F)), the multi-phasecomposition 102 at the hydrocyclone inlet 232 (P_(IN)), or combinationsof these, and control the at least one control valve, such as themedium-density fluid control valve 290, greater-density control valve292, lesser-density control valve 294, or combinations of these, basedon the comparison.

Referring to FIG. 9, the separator system 270 may include agreater-density fluid flowrate sensor 296. The greater-density fluidflowrate sensor 296 may be disposed proximate the permeate outlet 214 ofthe separator casing 210 or in a transfer conduit or pipe downstream ofthe permeate outlet 214. The greater-density fluid flowrate sensor 296may be operable to determine a flowrate Q₁₀₆ of the greater-densityfluid 106 passing out of the permeate outlet 214 of the separator casing210. The greater-density fluid flowrate sensor 296 may be any type ofcommercially-available device operable to determine the flowrate of afluid, such as the flowrate of a fluid passing through a pipe orconduit. The separator system 270 may also include the greater-densityfluid control valve 292 operatively coupled to the permeate outlet 214of the separator casing 210 or to a conduit or pipe downstream of thepermeate outlet 214. The greater-density fluid control valve 292 waspreviously described in relation to FIG. 8B and may have any of thepreviously described features.

Referring to FIG. 9, the separator system 270 may be operable to controloperation of the separator 200 based on the flowrate of thegreater-density fluid 106 passed out of the separator casing 210 fromthe permeate outlet 214. The separator system 270 may include thegreater-density fluid flowrate sensor 296 and the greater-density fluidcontrol valve 292. In some embodiments, the greater-density fluidcontrol valve 292 may be disposed downstream of the greater-densityfluid flowrate sensor 296. The separator system 270 may be operable tomeasure the flowrate of the greater-density fluid 106 using thegreater-density fluid flowrate sensor 296 operatively coupled to thepermeate outlet 214. The separator system 270 may be further operable toadjust the position of the greater-density fluid control valve 292 basedon the measured flowrate of the greater-density fluid 106.

The separator system 270 may include machine readable instructionsstored on the at least one memory module 174 that, when executed by theprocessor 172, may cause the separator system 270 to measure theflowrate Q₁₀₆ of the greater-density fluid 106 passing out of thepermeate outlet 214 of the separator casing 210, and control the atleast one control valve, such as the greater-density fluid control valve292, based on the measured flowrate Q₁₀₆ of the greater-density fluid106.

Referring now to FIG. 10, when the separator 200 includes an internalwall 216 dividing the chamber 212 into the first compartment 218 and thesecond compartment 220, the separator system 270 may be operable tocontrol operation of the separator 200 based on the flowrate of themulti-phase composition 102 introduced to the separator 200. Theseparator system 270 may include the separator casing 210 that includesan internal wall 216 dividing the chamber 212 into the first compartment218 comprising the permeate outlet 214 and the second compartment 220comprising the medium-density fluid outlet 224. The internal wall 216may be a flexible wall operable to equalize the pressure between thegreater-density fluid 106 in the first compartment 218 and themedium-density fluid 108 in the second compartment 220. The acceptedoutlet 236 of the hydrocyclone 230 may be in fluid communication withthe second compartment 220, and the permeate side 238 of the ceramicmembrane 250 may be in fluid communication with the first compartment218.

The separator system 270 may include an inlet flowrate sensor 298operatively coupled to the hydrocyclone inlet 232 or to a transfer pipeor conduit upstream of the hydrocyclone inlet 232. The inlet flowratesensor 298 may be operable to determine a flowrate of the multi-phasecomposition 102 introduced to the hydrocyclone inlet 232. The inletflowrate sensor 298 may be operable to transmit a signal indicative ofthe flowrate of the multi-phase composition 102 introduced to thehydrocyclone inlet 232. The inlet flowrate sensor 298 may becommunicatively coupled to the processor 172. The inlet flowrate sensor298 may be any type of commercially-available flowrate sensor orflowmeter operable to determine the flowrate of a fluid through aconduit.

The separator system 270 may include the medium-density fluid controlvalve 290 operatively coupled to the medium-density fluid outlet 224 ofthe second compartment 220 of the separator casing 210 or to a conduitor pipe downstream of the medium-density fluid outlet 224. Themedium-density fluid control valve 290 may be communicatively coupled tothe processor 172 and may be operable as previously described in thisdisclosure. The medium-density fluid control valve 290, the inletflowrate sensor 298, or both may be communicatively coupled to theprocessor 172 through the network interface 173.

Referring again to FIG. 10, the separator system 270 may be operable tocontrol operation of the separator 200 based on the flowrate of themulti-phase composition 102 introduced to the separator 200. Theseparator system 270 may be operable to measure the flowrate of themulti-phase composition 102 introduced to the separator 200 using theinlet flowrate sensor 298. The separator system 270 may be furtheroperable to adjust the position of the greater-density fluid controlvalve 292 based on the measured flowrate of the multi-phase composition102 introduced to the separator 200.

The separator system 270 may include machine readable instructionsstored on the at least one memory module 174 that, when executed by theprocessor 172, may cause the separator system 270 to measure theflowrate Q_(IN) of the multi-phase composition 102 introduced to thehydrocyclone 230 and control the at least one control valve, such as themedium-density fluid control valve 290, based on the measured flowrateQ_(IN) of the multi-phase composition 102 introduced to the hydrocyclone230. In some embodiments, the machine readable instructions stored onthe memory module 174, when executed by the processor 172, may cause theseparator system 270 to compare the flowrate Q_(IN) of the multi-phasecomposition 102 to a target flowrate and move the medium-density fluidcontrol valve 290 to a more open or more closed position based on thecomparison.

Referring again to FIG. 5, a method of separating the multi-phasecomposition 102 having an aqueous phase, an oleaginous phase, and asolid phase may include passing the multi-phase composition 102 to theseparator 200, which may have any of the features or characteristicsprevious described in this disclosure for separator 200. The separator200 may be operable to separate the multi-phase composition 102 into thelesser-density fluid 104, the medium-density fluid 108, and thegreater-density fluid 106. The method may further include collecting thelesser-density fluid 104 from the reject outlet 234 of the hydrocyclone230, collecting the greater-density fluid 106 from the permeate outlet214 of the separator casing 210, and collecting the medium-density fluid108 from the medium-density fluid outlet 224 of the separator 200.

Referring again to FIG. 8A, the method may further include determining apressure of the medium-density fluid 108 at the accepted outlet 236 ofthe hydrocyclone 230 (P_(OUT)), a pressure of the greater-density fluid106 in the separator casing 210 (P_(F)), or both, and increasing ordecreasing flow of the medium-density fluid 108 passed out of themedium-density fluid outlet 224 of the separator 200 based on themeasured pressure. Increasing or decreasing the flow of themedium-density fluid 108 passed out of the medium-density fluid outlet224 may decrease or increase, respectively, the pressure P_(OUT) of themedium-density fluid 108 at the accepted outlet 236 of the hydrocyclone230. The flow of the medium density fluid 108 passed out of themedium-density fluid outlet 224 may be increased or decreased by movingthe medium-density fluid control valve 290 to a more open or a moreclosed position, respectively. In some embodiments, the method mayinclude determining the pressure of the medium-density fluid 108 at theaccepted outlet 236 (P_(OUT)) and the pressure of the greater-densityfluid 106 in the separator casing 210 (P_(F)), comparing the pressure ofthe medium-density fluid 108 at the accepted outlet 236 (P_(OUT)) to thepressure of the greater-density fluid 106 in the separator casing 210(P_(F)), and increasing or decreasing flow of the medium-density fluid108 passed out of the medium-density fluid outlet 224 based on thecomparison.

Referring to FIG. 8B, in one or more embodiments, the method may furtherinclude determining a pressure of the medium-density fluid 108 at theaccepted outlet 236 of the hydrocyclone 230 (P_(OUT)), a pressure of thegreater-density fluid 106 in the separator casing 210 (P_(F)), apressure of the multi-phase composition 102 introduced to thehydrocyclone 230, or combinations of these, and increasing or decreasingflow of the medium-density fluid 108 passed out of the medium-densityfluid outlet 224, the greater-density fluid 106 passed out of thegreater-density fluid outlet 214, the lesser-density fluid 104 passedout of the lesser-density fluid outlet 234, or combinations of thesebased on the measured pressure.

Referring to FIG. 9, the method may include determining the flowrate ofthe greater-density fluid 106 at the permeate outlet 214 of theseparator casing 210 and increasing or decreasing the flowrate of thegreater-density fluid 106 passed out of the permeate outlet 214 based onthe measured flowrate. The flowrate of the greater-density fluid 106passed out the permeate outlet 214 may be increased or decreased bymoving the greater-density fluid control valve 292 to a more open or amore closed position, respectively. The method may further includecomparing the determined flowrate of the greater-density fluid 106 atthe permeate outlet 214 with a target flowrate of the greater-densityfluid 106 and increasing or decreasing the flowrate of thegreater-density fluid control valve 292 based on the comparison.

Referring to FIG. 10, the separator 200 may include the flexibleinternal wall 216 dividing the chamber 212 into the first compartment218 that includes the permeate outlet 214 and the second compartment 220that includes the medium-density fluid outlet 224. The accepted outlet236 of the hydrocyclone 230 may be in fluid communication with thesecond compartment 220, and the permeate side 258 of the ceramicmembrane 250 may be in fluid communication with the first compartment218. The method may further include determining the flowrate Q₁₀₂ of themulti-phase composition 102 introduced to the hydrocyclone 230 andincreasing or decreasing a flowrate of the medium-density fluid 108passed out of the medium-density fluid outlet 224 based on the measuredflowrate. The method may further include comparing the determinedflowrate Q₁₀₂ to a target flowrate for the multi-phase composition 102and increasing or decreasing the flowrate of the medium-density fluid108 passed out of the medium-density fluid outlet 224 based on thecomparison. The flowrate of the medium-density fluid 108 passed out ofthe medium-density fluid outlet 224 may be increased or decreased bymoving the medium-density fluid control valve 290 to a more open or amore closed position, respectively.

Although the separator systems 270 are depicted in FIGS. 8, 9, and 10 asincluding the computing device 171 having processor 172 communicativelycoupled to various pressure sensors, flowrate sensors, and controlvalves, it is understood that the methods of pressure drop ratio controlor flowrate control of the separator 200 may be accomplished using oneor more analog techniques or devices as an alternative to or in additionto controls using the computing device 171. It is intended for themethods of the present disclosure to include implementation of methodsteps using either digital or analog technologies.

The separators 100, 200 and separator systems 170, 270 of the presentdisclosure may be used to separate multi-phase compositions 102 into aplurality of streams of different density. For example, the separators100, 200 and separator system 170, 270 may be used to process producedwater from hydrocarbon drilling or production operations. Produced waterfrom hydrocarbon drilling and production may include an aqueous phase,an oleaginous phase, and suspended solids. Produced water may bedirectly introduced to the separators 100, 200 or the presentdisclosure, such as when used on drilling platforms for underwaterdrilling operations. In some situations, the separators 100, 200 may beincorporated into a larger gas oil separation plant (GOSP) in which theproduced water may be first introduced to an oil/water gravity separatorsystem and an effluent from the oil/water gravity separator system maybe introduced to the separators 100, 200 of the present disclosure. Theseparators 100, 200 of the present disclosure may also be useful forseparating multi-phase compositions in other industries, such as foodprocessing, mining, environmental remediation, chemical processing,manufacturing, municipal or storm water treatment, or other industries.

The separators 100, 200 and separator system 170, 270 of the presentdisclosure may be operable to produce a medium-density fluid 108 that isprimarily water. The medium density fluid 108 produced using theseparators 100, 200 of the present disclosure may have a concentrationof oil of less than 5 parts per million by volume and reduced suspendedsolids compared to the starting multi-phase composition 102. Themedium-density fluid 108 (water) produced by the separators 100, 200 maybe capable of meeting water quality standards for use of the water inoil field applications, such as reservoir flooding, hydraulicfracturing, or other enhanced oil recovery methods. In someapplications, the medium-density fluid 108 may be passed to a downstreamprocess for further treatment, such as desalination.

The lesser-density fluid 104 may include the greatest portions of oildroplets and other organic compounds. The lesser-density fluid 104 maybe passed to one or more downstream processing systems for recoveringoil and other organic compounds. The greater-density fluid 106 mayinclude the greatest portion of solids, such as sand, rock particles,dirt or other solid particles. The greater-density fluid 106 may beprocessed for disposal. In some systems, the greater-density fluid 106may be passed back to a settling system such as a settling tank or pond,an oil/water gravity separator of a GOSP, or other treatment process.

The computing device 171 described in the present disclosure is onecontemplated example of a suitable computing device and does not suggestany limitation on the scope of any embodiments presented. Nothingillustrated or described with respect to the computing device 171 shouldbe interpreted as being required or as creating any type of dependencywith respect to any element or plurality of elements of the presentdisclosure. It is understood that various methods and control schemesdescribed in the present disclosure may be implemented using one or moreanalog control devices in addition to or as an alternative to thecomputing device 171. The computing device 171 may include, but is notlimited to, an industrial controller, desktop computer, laptop computer,server, client computer, tablet, smartphone, or any other type of devicethat can send data, receive data, store data, and perform one or morecalculations. In an embodiment, the computing device 171 includes atleast one processor 172 and at least one memory module 174 (non-volatilememory 708 and/or volatile memory 710). The computing device 171 caninclude a display and may be communicatively coupled to one or moreoutput devices, such as, but not limited to, the retentate control valve190, the permeate control valve 192, the lesser-density fluid controlvalve 194, the inlet pump 176, medium-density fluid control valve 290,greater-density fluid control valve 292, or combinations of these. Thecomputing device 171 may further include one or more input devices whichcan include, by way of example, any type of mouse, keyboard, keypad,push button array, switches, disk or media drive, memory stick (thumbdrive), memory card, pen, touch-input device, biometric scanner, audioinput device, pressure sensor, flowrate sensor, temperature sensor,other sensor, or combinations of these. In one or more embodiments, theinput devices may include one or a plurality of the pressure sensorsdisclosed in the present disclosure, the flowrate sensors disclosed inthe present disclosure, or combinations of these.

The at least one memory module 174 of the computing device 171 mayinclude a non-volatile memory (ROM, flash memory, etc.), volatile memory(RAM, etc.), or a combination of these. The computing device 171 caninclude a network interface 173, which can facilitate communication withthe input devices and output devices or over a network via wires, via awide area network, via a local area network, via a personal areanetwork, via a cellular network, via a satellite network, or acombination of these. Suitable local area networks may include wiredEthernet and/or wireless technologies such as, for example, wirelessfidelity (Wi-Fi). Suitable personal area networks may include wirelesstechnologies such as, for example, IrDA, Bluetooth, Wireless USB,Z-Wave, ZigBee, other near field communication protocols, orcombinations of these. Suitable personal area networks may similarlyinclude wired computer buses such as, for example, USB and FireWire.Suitable cellular networks include, but are not limited to, technologiessuch as LTE, WiMAX, UMTS, CDMA, and GSM. Network interface 173 can becommunicatively coupled to any device capable of transmitting data,receiving data, or both via a network.

The hardware of the network interface 173 can include a communicationtransceiver for sending, receiving, or both, any wired or wirelesscommunication. Various components, such as the pressure sensors,flowrate sensors, pumps, control valves, or other sensors or controldevices may utilize the network interface 173 to communicate with theprocessor 172 through the network. For example, the hardware of thenetwork interface 173 may include an antenna, a modem, LAN port, Wi-Ficard, WiMax card, mobile communications hardware, near-fieldcommunication hardware, satellite communication hardware and/or anywired or wireless hardware for communicating with other networks and/ordevices.

The one or more memory modules 174 may include one or a plurality ofcomputer readable storage mediums, each of which may be either acomputer readable storage medium or a computer readable signal medium. Acomputer readable storage medium may reside, for example, within aninput device, non-volatile memory, volatile memory, or any combinationthereof. A computer readable storage medium can include tangible mediathat is able to store instructions associated with, or used by, a deviceor system. A computer readable storage medium includes, by way ofnon-limiting examples: RAM, ROM, cache, fiber optics, EPROM/Flashmemory, CD/DVD/BD-ROM, hard disk drives, solid-state storage, optical ormagnetic storage devices, diskettes, electrical connections having awire, or any combination thereof. A computer readable storage medium mayalso include, for example, a system or device that is of a magnetic,optical, semiconductor, or electronic type. Computer readable storagemedia and computer readable signal media are mutually exclusive.

A computer readable signal medium can include any type of computerreadable medium that is not a computer readable storage medium and mayinclude, for example, propagated signals taking any number of forms suchas optical, electromagnetic, or a combination thereof. A computerreadable signal medium may include propagated data signals containingcomputer readable code, for example, within a carrier wave.

The depictions of the computing device 171 in the drawings aresimplified representations of the computing device 171. Many componentsof the computing device 171 have been omitted for purposes of clarity.Assembling various hardware components into a functioning computingdevice 171 is considered to be part of the ordinary skill in the art.

It is noted that recitations herein of a component of the presentdisclosure being “configured,” “structured,” or “programmed” in aparticular way, to embody a particular property, or to function in aparticular manner, are structural recitations, as opposed to recitationsof intended use. More specifically, the references herein to the mannerin which a component is “configured,” “structured,” or “programmed”denotes an existing physical condition of the component and, as such, isto be taken as a definite recitation of the structural characteristicsof the component.

EXAMPLES

The following examples illustrate one or more additional features of theseparators of the present disclosure. In the following examples, aseparator according to the separator 100 depicted in FIG. 1 was modeled.Operation of the hydrocyclone 130 was modeled based on data obtainedfrom existing hydrocyclones typically used for water-oil separations inthe hydrocarbon drilling, production, and refining industry. Referringto FIG. 11, the relationship between the inlet flowrate (Q₁₀₂) of thefluid introduced to the hydrocyclone 130 and the pressure drop from thehydrocyclone inlet 132 to the accepted outlet 136 (dP_(Water)) isdepicted.

Referring to FIG. 3, the outlet pressure (P_(OUT)) of the intermediatefluid 140 at the accepted outlet 136 and the pressure (P_(L)) of thelesser-density fluid 104 at the reject outlet 134 as a function of thepressure drop (dP_(Water)) and the inlet pressure (P_(IN)) are providedbelow in Equation 3 (EQU. 3) and Equation 4 (EQU. 4).P _(OUT) =P _(IN) −dP _(Water)  EQU. 3P _(L) =P _(IN) −C×dP _(Water)  EQU. 4

The outlet pressure P_(H) of the greater-density fluid 106 downstream ofthe greater-density fluid outlet 124 is assumed to be constant at 6.9bar (690 kilopascals (kPa) or 100 pounds per square inch (psi)). Withthis outlet pressure P_(H) and the inlet pressure P_(IN), theoperational envelope for the system may be calculated for C=2 (providedin Table 1) and C=1.5 (provided in Table 2). The inlet flowrates Q₁₀₂are provided in Tables 1 and 2 in units of cubic meters per hour (m³/h).

TABLE 1 Operational envelop of inlet pressure P_(IN) (kPa) as a functionof inlet flowrate Q₁₀₂ and a hypothetical input of pressure P_(IN)* fora pressure drop ration C of 2.0 Q₁₀₂ Hypothetical Input of PressureP_(IN)* (kPa) (m³/h) 800 900 1000 1100 1200 1300 1400 1500 1600 17001800 1900 1.77 — — — — — — — — — — — — 1.99 772 — — — — — — — — — — —2.27 — 766 966 — — — — — — — — — 2.47 — — 759 959 1159 — — — — — — —2.65 — — — 752 952 1152 1352 — — — — — 2.88 — — — — 745 945 1145 13451545 — — — 3.05 — — — — — 738 938 1138 1338 1538 1738 — 3.18 — — — — — —731 931 1131 1331 1531 1731 4.50 — — — — — — — — — — — —

TABLE 2 Operational envelop of inlet pressure P_(IN) (kPa) as a functionof inlet flowrate Q₁₀₂ and a hypothetical input of pressure P_(IN)* fora pressure drop ration C of 1.5 Q₁₀₂ Hypothetical Input of PressureP_(IN)* (kPa) (m³/h) 800 900 1000 1100 1200 1300 1400 1500 1600 17001800 1900 1.99 — — — — — — — — — — — — 2.27 738 — — — — — — — — — — —2.47 — 766 966 — — — — — — — — — 2.65 — — 793 993 1193 — — — — — — —2.88 — — — 821 1021 1221 — — — — — — 3.05 — — — — 848 1048 1248 1448 — —— — 3.18 — — — — — 876 1076 1276 1476 1676 — — 4.50 — — — — — — — — — —— —

For a pressure drop ratio C equal to 2 and inlet flowrate Q₁₀₂ in arange of from 2.65 m³/h to 3.18 m³/h, the water recovery rate from theseparator 100 may be calculated based on a commercial cross-flow ceramicmembrane having a length of 1 meter and 10 tubes having an innerdiameter of 1 centimeter. The ceramic membrane has an average pore sizeof 140 nanometers and is constructed of a ceramic material comprisingtitania (TiO₂) and zirconia (ZrO₂). The specific permeate flux of theceramic membrane 150 and, therefore, the flowrate Q_(F) for themedium-density fluid 108 passing through the ceramic membrane 150 can bedetermined according to the following Equation 5 (EQU. 5) for a linearspeed of the fluid in the tubes of 4.5 meters per second.Q _(F)=3990×TMP; 0≤TMP≤0.5 bar  EQU. 5

In EQU. 5, TMP is the transmembrane pressure in bar (where 1 bar=100kilopascals (kPa)). EQU. 5 was derived from the relationship between thespecific permeate flux and the transmembrane pressure (TMP) which isgraphically depicted in FIG. 12.

With these parameters and using Equations 1-5, the water recovery R_(C)of the system is calculated for one ceramic membrane 150 (previouslydescribed), a transmembrane pressure of 0.5 bar (50 kPa), a pressuredrop ratio C of 2, a reject ratio R_(R) of 2%, and an inlet flowrate(Q_(IN)) in a range of from 2.65 m³/h to 3.18 m³/h. The inlet pressure(P_(IN)) ranges from 13.5 bar (1350 kPa) to 7.3 bar (730 kPa) over therange of the inlet flowrate (Q_(IN)), respectively. The flowrate (Q_(F))of the medium-density fluid 108 is maintained constant at 636.84 litersper hour (0.63684 m³/hr) and the outlet pressure (P_(H)) of thegreater-density fluid 106 is maintained constant at 6.9 bar (690 kPa).The water recovery R_(C) is calculated as the ratio between the permeateflowrate Q_(F) (flowrate of the medium-density fluid 108 passing throughthe ceramic membrane 150) and the amount of water entering the ceramicmembranes Qout (Q₁₀₂-Q₁₀₄). The equation for calculating water recoveryR_(C) is shown below in Equation 6 (EQU. 6).

$\begin{matrix}{{R_{C} = {\frac{Q_{F}}{Q_{OUT}} \times 100}};{Q_{OUT} = {Q_{102} - Q_{104}}}} & {{EQU}.\mspace{14mu} 6}\end{matrix}$The water recovery calculated for these Examples is provided in Table 3as a percentage.

TABLE 3 Calculated parameters for the separator 100 of the Examples.Q_(IN) m³/h P_(IN) P_(Out) P_(F) P_(L) Q₁₀₆ Q₁₀₄ Q_(OUT) Rc (Q₁₀₂) barbar bar bar m³/h m³/h m³/h % Stage 2.65 13.52 9.17 7.53 4.34 1.96 0.052.60 24.52 2 2.88 11.45 8.48 7.19 2.97 2.19 0.06 2.82 22.55 2 3.05 9.387.79 6.84 1.59 2.35 0.06 2.99 21.33 2 3.18 7.31 7.10 6.50 0.21 2.48 0.063.12 20.44 2

The water recovery R_(C) in these conditions will be of approximately25% for a surface area of 0.32 m², which is the surface area for asingle ceramic membrane unit as described in these examples. If a waterrecovery of 50% is required, the surface area of the ceramic membranewill double. Therefore, two ceramic membranes may be provided toincrease the water recovery to 50%, as indicated by the stage equal to 2in Table 3. The water recovery may be further increased by addingadditional ceramic membranes.

In a first aspect of the present disclosure, a separator includes aseparator casing defining a chamber and having a permeate outlet, atleast one hydrocyclone disposed within the separator casing, and atleast one ceramic membrane disposed within the separator casing anddownstream of an accepted outlet of the hydrocyclone. The at least onehydrocyclone may include a hydrocyclone inlet, a tapered sectiondownstream of the hydrocyclone inlet, a reject outlet proximate a wideend of the tapered section, and an accepted outlet proximate a narrowend of the tapered section. The ceramic membrane may include at leastone cylindrical tube, a membrane inlet, a retentate outlet, a retentateside defining the at least one cylindrical tube, and a permeate side,where the permeate side is in fluid communication with the chamber.

A second aspect of the present disclosure may include the first aspect,in which the membrane inlet of the at least one ceramic membrane may bein fluid communication with the accepted outlet of the at least onehydrocyclone.

A third aspect of the present disclosure may include any one of thefirst or second aspects, in which the at least one ceramic membrane maycomprise a plurality of cylindrical tubes extending from the membraneinlet to the retentate outlet.

A fourth aspect of the present disclosure may include any one of thefirst through third aspects, in which the separator may include aplurality of ceramic membranes, where the membrane inlet of each of theplurality of ceramic membranes may be in fluid communication with theaccepted outlet of the at least one hydrocyclone and the permeate sideof each of the plurality of ceramic membranes may be in fluidcommunication with the chamber.

A fifth aspect of the present disclosure may include any one of thefirst through fourth aspects, in which the separator casing may compriseone or a plurality of internal walls dividing the chamber into at leasta first compartment and a second compartment. The first compartment maybe in fluid communication with the accepted outlet of the at least onehydrocyclone and the membrane inlet of the at least one ceramicmembrane. The second compartment may include the permeate outlet and maybe in fluid communication with the permeate side of the ceramicmembrane.

A sixth aspect of the present disclosure may include the fifth aspect,in which the first compartment may provide a flow path that fluidlycouples the accepted outlet of the at least one hydrocyclone to themembrane inlet of the at least one ceramic membrane.

A seventh aspect of the present disclosure may include any one of thefifth or sixth aspects, in which the separator casing may comprise athird compartment in fluid communication with the retentate outlet ofthe at least one ceramic membrane and having a greater-density fluidoutlet.

An eighth aspect of the present disclosure may include any one of thefirst through seventh aspects, in which the at least one ceramicmembrane may have an average pore size of less than or equal to 0.5micrometers.

A ninth aspect of the present disclosure may include any one of thefirst through eighth aspects, in which the at least one ceramic membranemay have an average pore size of from 0.005 micrometers to 0.5micrometers.

A tenth aspect of the present disclosure may include any one of thefirst through ninth aspects, where the at least one hydrocyclone may beoperable to separate a multi-phase composition comprising a solid phase,an aqueous phase, and an oleaginous phase into a lesser-density fluidand an intermediate fluid and the at least one ceramic membrane may beoperable to separate the intermediate fluid into a greater-density fluidand a medium-density fluid. The greater-density fluid may pass out ofthe retentate outlet of the at least one ceramic membrane and themedium-density fluid may pass through the at least one ceramic membraneto the chamber of the separator casing.

An eleventh aspect of the present disclosure may include any one of thefirst through tenth aspects, comprising a plurality of hydrocyclones anda plurality of ceramic membranes.

A twelfth aspect of the present disclosure may be directed to aseparator system comprising the separator of any one of the firstthrough eleventh aspects. The separator system may further comprise atleast one pressure sensor operatively coupled to the hydrocyclone inlet,the reject outlet, the membrane inlet, the retentate outlet of theceramic membrane, or the separator casing. The separator system mayfurther include at least one control valve operatively coupled to apermeate outlet or a greater-density fluid outlet of the separatorcasing, at least one processor communicatively coupled to the at leastone pressure sensor and the at least one control valve, and at least onememory module communicatively coupled to the processor.

A thirteenth aspect of the present disclosure may include the twelfthaspect, further comprising machine readable instructions stored on theat least one memory module. The machine readable instructions, whenexecuted by the at least one processor, may cause the separator systemto measure a pressure of at least one of a multi-phase compositionintroduced to the at least one hydrocyclone, a lesser-density fluid atthe reject outlet, an intermediate fluid passed from the accepted outletof the at least one hydrocyclone to the membrane inlet, a medium-densityfluid in the separator casing, or a greater-density fluid at thegreater-density fluid outlet of the separator casing. The machinereadable instructions may further cause the separator system to controlthe at least one control valve based on the measured pressure.

A fourteenth aspect of the present disclosure may include the thirteenthaspect, where the machine readable instructions, when executed by the atleast one processor, may cause the separator system to compare themeasured pressure against a target pressure for the multi-phasecomposition introduced to the at least one hydrocyclone, thelesser-density fluid at the reject outlet, the intermediate fluid passedfrom the accepted outlet of the at least one hydrocyclone to themembrane inlet, the medium-density fluid in the separator casing, or thegreater-density fluid at the greater-density fluid outlet of theseparator casing. The machine readable instructions may further causethe separator system to control the at least one control valve based onthe comparison.

A fifteenth aspect of the present disclosure may include any one of thetwelfth through fourteenth aspects, where the at least one pressuresensor may include one or a plurality of a hydrocyclone inlet pressuresensor operatively coupled to the hydrocyclone inlet of the at least onehydrocyclone, a lesser-density fluid pressure sensor operatively coupledto the reject outlet of the at least one hydrocyclone, an intermediatefluid pressure sensor operatively coupled to the membrane inlet, aretentate pressure sensor operatively coupled to the greater-densityfluid outlet, or a permeate pressure sensor operatively coupled to theseparator casing.

A sixteenth aspect of the present disclosure may include any one of thetwelfth through fifteenth aspects, where the at least one control valvemay comprise a permeate control valve operatively coupled to thepermeate outlet of the separator casing and a retentate control valveoperatively coupled to the greater-density fluid outlet.

A seventeenth aspect of the present disclosure may include any one ofthe twelfth through sixteenth aspects, further comprising a flowratesensor operatively coupled to the greater-density fluid outlet of theseparator casing, where the flowrate sensor may be configured to measurea flowrate of the greater-density fluid at the greater-density fluidoutlet of the separator casing.

An eighteenth aspect of the present disclosure may include theseventeenth aspect, comprising machine readable instructions stored onthe at least one memory module, where the machine readable instructions,when executed by the at least one processor, may cause the separatorsystem to measure a flowrate of the greater-density fluid passing out ofthe greater-density fluid outlet of the separator casing, and controlthe at least one control valve based on the measured flowrate of thegreater-density fluid.

A nineteenth aspect of the present disclosure may be directed to amethod of separating a multi-phase composition having an aqueous phase,an oleaginous phase, and a solid phase, the method comprising passingthe multi-phase composition to the separator of any one of the firstthrough eleventh aspects, where the separator is operable to separatethe multi-phase composition into a lesser-density fluid, amedium-density fluid, and a greater-density fluid.

A twentieth aspect of the present disclosure may be directed to a methodof separating a multi-phase composition having an aqueous phase, anoleaginous phase, and a solid phase, the method comprising passing themulti-phase composition to a separator operable to separate themulti-phase composition into a lesser-density fluid, a medium-densityfluid, and a greater-density fluid. The separator may include aseparator casing defining a chamber and having a permeate outlet, atleast one hydrocyclone disposed within the separator casing and havingan accepted outlet and a reject outlet, and at least one ceramicmembrane disposed within the separator casing and downstream of theaccepted outlet of the hydrocyclone, the ceramic membrane comprising atleast one cylindrical tube, a membrane inlet, a retentate outlet, aretentate side defining the at least one cylindrical tube, and apermeate side, where the permeate side is in fluid communication withthe chamber.

A twenty-first aspect of the present disclosure may include thetwentieth aspect, in which the separator comprises the separator of anyof the first through eleventh aspects.

A twenty-second aspect of the present disclosure may include any one ofthe nineteenth through twenty-first aspects, further comprisingcollecting the lesser-density fluid from the reject outlet of the atleast one hydrocyclone, collecting the greater-density fluid from thegreater-density fluid outlet of the separator casing, and collecting themedium-density fluid from the permeate outlet of the separator casing.

A twenty-third aspect of the present disclosure may include any one ofthe nineteenth through twenty-second aspects, further comprisingmeasuring a pressure of one or a plurality of the following: themulti-phase composition at the hydrocyclone inlet of the at least onehydrocyclone, the lesser-density fluid at the reject outlet of the atleast one hydrocyclone, an intermediate fluid passed from the acceptedoutlet of the at least one hydrocyclone to the membrane inlet, themedium-density fluid in the separator casing, or the greater-densityfluid at the greater-density fluid outlet of the separator casing. Themethod may further include adjusting a position of a retentate controlvalve at the greater-density fluid outlet, a permeate control valve atthe permeate outlet, a lesser-density fluid control valve at the rejectoutlet of the at least one hydrocyclone, or combinations of these, basedon the measured pressure. Adjusting the position of one or more of theretentate control valve, the permeate control valve, or thelesser-density fluid control valve may increase or decrease the pressureof one or a plurality of the multi-phase composition, the lesser-densityfluid, the intermediate fluid, the greater-density fluid, themedium-density fluid, or combinations of these.

A twenty-fourth aspect of the present disclosure may include thetwenty-third aspect, further comprising comparing the measured pressureagainst a target pressure and adjusting a position of the retentatecontrol valve at the greater-density fluid outlet, the permeate controlvalve at the permeate outlet, the lesser-density fluid control valve atthe reject outlet of the at least one hydrocyclone, or combinations ofthese, based on the comparison.

A twenty-fifth aspect of the present disclosure may include any one ofthe nineteenth through twenty-fourth aspects, further comprisingmeasuring a flowrate of the greater-density fluid passing out of thegreater-density fluid outlet of the separator casing and increasing ordecreasing the flowrate of the greater-density fluid from thegreater-density fluid outlet based on the measured pressure.

A twenty-sixth aspect of the present disclosure may include thetwenty-fifth aspect, further comprising adjusting a position of apermeate control valve at the permeate outlet, a lesser-density fluidcontrol valve at the reject outlet of the at least one hydrocyclone, orboth, in response to increasing or decreasing the flowrate of thegreater-density fluid from the greater-density fluid outlet. Adjustingthe positon of the permeate control valve or the lesser-density fluidcontrol valve may increase or decrease the pressure of one or more ofthe multi-phase composition, the lesser-density fluid, the intermediatefluid, the greater-density fluid, the medium-density fluid, orcombinations of these.

It should now be understood that various aspects of the apparatus,systems, and methods for separating multi-phase compositions, such asproduced water, are described and such aspects may be utilized inconjunction with various other aspects.

Throughout this disclosure ranges are provided for various processingparameters and operating conditions for the apparatus, systems, andmethods for separating multi-phase compositions and the compositions ofvarious streams and mixtures. It will be appreciated that when one ormore explicit ranges are provided the individual values and thesub-ranges formed within the range are also intended to be provided asproviding an explicit listing of all possible combinations isprohibitive. For example, a provided range of 1-10 also includes theindividual values, such as 1, 2, 3, 4.2, and 6.8, as well as all theranges that may be formed within the provided bounds, such as 1-8, 2-4,6-9, and 1.3-5.6.

It is noted that recitations herein of “at least one” component,element, etc., should not be used to create an inference that thealternative use of the articles “a” or “an” should be limited to asingle component, element, etc.

It should be apparent to those skilled in the art that variousmodifications and variations can be made to the described embodimentswithout departing from the spirit and scope of the claimed subjectmatter. Thus, it is intended that the specification cover themodifications and variations of the various described embodimentsprovided such modifications and variations come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A separator comprising: a separator casing defining a chamber and having a permeate outlet; at least one hydrocyclone disposed within the separator casing, the at least one hydrocyclone comprising: a hydrocyclone inlet; a tapered section downstream of the hydrocyclone inlet; a reject outlet proximate a wide end of the tapered section; and an accepted outlet proximate a narrow end of the tapered section; and at least one ceramic membrane disposed within the separator casing and downstream of the accepted outlet of the hydrocyclone, the ceramic membrane comprising at least one cylindrical tube, a membrane inlet, a retentate outlet, a retentate side defining the at least one cylindrical tube, and a permeate side, where the permeate side is in fluid communication with the chamber.
 2. The separator of claim 1, in which the membrane inlet of the at least one ceramic membrane is in fluid communication with the accepted outlet of the at least one hydrocyclone.
 3. The separator of claim 1, in which the at least one ceramic membrane comprises a plurality of cylindrical tubes extending from the membrane inlet to the retentate outlet.
 4. The separator of claim 1, in which the separator comprises a plurality of ceramic membranes, where the membrane inlet of each of the plurality of ceramic membranes is in fluid communication with the accepted outlet of the at least one hydrocyclone and the permeate side of each of the plurality of ceramic membranes is in fluid communication with the chamber.
 5. The separator of claim 1, in which the separator casing comprises one or a plurality of internal walls dividing the chamber into at least a first compartment and a second compartment, in which: the first compartment is in fluid communication with the accepted outlet of the at least one hydrocyclone and the membrane inlet of the at least one ceramic membrane; and the second compartment comprises the permeate outlet and is in fluid communication with the permeate side of the ceramic membrane.
 6. The separator of claim 5, in which the first compartment provides a flow path that fluidly couples the accepted outlet of the at least one hydrocyclone to the membrane inlet of the at least one ceramic membrane.
 7. The separator of claim 5, in which the separator casing comprises a third compartment in fluid communication with the retentate outlet of the at least one ceramic membrane and having a greater-density fluid outlet.
 8. The separator of claim 1, in which the at least one ceramic membrane comprises an average pore size of less than or equal to 0.5 micrometers.
 9. The separator of claim 1, where the at least one hydrocyclone is operable to separate a multi-phase composition comprising a solid phase, an aqueous phase, and an oleaginous phase into a lesser-density fluid and an intermediate fluid and the at least one ceramic membrane is operable to separate the intermediate fluid into a greater-density fluid and a medium-density fluid, where the greater-density fluid passes out of the retentate outlet of the at least one ceramic membrane and the medium-density fluid passes through the at least one ceramic membrane to the chamber of the separator casing.
 10. The separator of claim 1, comprising a plurality of hydrocyclones and a plurality of ceramic membranes.
 11. A separator system comprising: the separator of claim 1; at least one pressure sensor operatively coupled to the hydrocyclone inlet, the reject outlet, the membrane inlet, the retentate outlet of the ceramic membrane, or the separator casing; at least one control valve operatively coupled to a permeate outlet or a greater-density fluid outlet of the separator casing; at least one processor communicatively coupled to the at least one pressure sensor and the at least one control valve; and at least one memory module communicatively coupled to the processor.
 12. The separator system of claim 11, further comprising machine readable instructions stored on the at least one memory module, where the machine readable instructions, when executed by the at least one processor, cause the separator system to: measure a pressure of at least one of a multi-phase composition introduced to the at least one hydrocyclone, a lesser-density fluid at the reject outlet, an intermediate fluid passed from the accepted outlet of the at least one hydrocyclone to the membrane inlet, a medium-density fluid in the separator casing, or a greater-density fluid at the greater-density fluid outlet of the separator casing; and control the at least one control valve based on the measured pressure.
 13. The separator system of claim 12, where the at least one pressure sensor comprises one or a plurality of: a hydrocyclone inlet pressure sensor operatively coupled to the hydrocyclone inlet of the at least one hydrocyclone; a lesser-density fluid pressure sensor operatively coupled to the reject outlet of the at least one hydrocyclone; an intermediate fluid pressure sensor operatively coupled to the membrane inlet; a retentate pressure sensor operatively coupled to the greater-density fluid outlet; or a permeate pressure sensor operatively coupled to the separator casing.
 14. The separator system of claim 12, where the at least one control valve comprises a permeate control valve operatively coupled to the permeate outlet of the separator casing and a retentate control valve operatively coupled to the greater-density fluid outlet.
 15. The separator system of claim 12, further comprising: a flowrate sensor operatively coupled to the greater-density fluid outlet of the separator casing, where the flowrate sensor is configured to measure a flowrate of the greater-density fluid at the greater-density fluid outlet of the separator casing; and machine readable instructions stored on the at least one memory module, where the machine readable instructions, when executed by the at least one processor, cause the separator system to: measure a flowrate of the greater-density fluid passing out of the greater-density fluid outlet of the separator casing; and control the at least one control valve based on the measured flowrate of the greater-density fluid.
 16. A method of separating a multi-phase composition having an aqueous phase, an oleaginous phase, and a solid phase, the method comprising passing the multi-phase composition to a separator operable to separate the multi-phase composition into a lesser-density fluid, a medium-density fluid, and a greater-density fluid, the separator comprising: a separator casing defining a chamber and having a permeate outlet; at least one hydrocyclone disposed within the separator casing and having an accepted outlet and a reject outlet; and at least one ceramic membrane disposed within the separator casing and downstream of the accepted outlet of the hydrocyclone, the ceramic membrane comprising at least one cylindrical tube, a membrane inlet, a retentate outlet, a retentate side defining the at least one cylindrical tube, and a permeate side, where the permeate side is in fluid communication with the chamber.
 17. The method of claim 16, further comprising: collecting the lesser-density fluid from the reject outlet of the at least one hydrocyclone; collecting the greater-density fluid from a greater-density fluid outlet of the separator casing; and collecting the medium-density fluid from the permeate outlet of the separator casing.
 18. The method of claim 16, further comprising: measuring a pressure of one or a plurality of the following: the multi-phase composition at a hydrocyclone inlet of the at least one hydrocyclone; the lesser-density fluid at the reject outlet of the at least one hydrocyclone; an intermediate fluid passed from the accepted outlet of the at least one hydrocyclone to the membrane inlet; the medium-density fluid in the separator casing; or the greater-density fluid at a greater-density fluid outlet of the separator casing; and adjusting a position of a retentate control valve at the greater-density fluid outlet, a permeate control valve at the permeate outlet, a lesser-density fluid control valve at the reject outlet of the at least one hydrocyclone, or combinations of these, based on the measured pressure, where adjusting the position of one or more of the retentate control valve, the permeate control valve, or the lesser-density fluid control valve increases or decreases the pressure of one or a plurality of the multi-phase composition, the lesser-density fluid, the intermediate fluid, the greater-density fluid, the medium-density fluid, or combinations of these.
 19. The method of claim 16, further comprising: measuring a flowrate of the greater-density fluid passing out of a greater-density fluid outlet of the separator casing; and increasing or decreasing the flowrate of the greater-density fluid from the greater-density fluid outlet based on the measured flowrate.
 20. The method of claim 19, further comprising adjusting a position of a permeate control valve at the permeate outlet, a lesser-density fluid control valve at the reject outlet of the at least one hydrocyclone, or both, in response to increasing or decreasing the flowrate of the greater-density fluid from the greater-density fluid outlet, where adjusting the position of the permeate control valve or the lesser-density fluid control valve increases or decreases a pressure of one or more of the multi-phase composition, the lesser-density fluid, an intermediate fluid, the greater-density fluid, the medium-density fluid, or combinations of these. 